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DeviceNet

User�s Guide

P/N 715-0016 V1.2

Essentials

DeviceNet Cable Essentials

AutoSearch Mode

Read this first!

DeviceNet cablehas five wiresinside. Each has aspecific purposewhich is referencedin this manual.

CANL(messages)

Shield

V-(power)

V+(power)

CANH(messages)

AutoSearch mode saves you time by finding the networkmeasurements that exceed acceptable limits. It works byexamining all measurements and then pinpointing anythat exceed or are close to specified limits. Foreach problem measurement NetMeter indicates themeasurement's switch position number in the upper leftcorner of the display. Rotate the selector switch to theindicated setting to view related measurements.

NetMeter requires 2 ‘AA’ Alkaline batteries for viewingmeasurements offline. NetMeter must be plugged into apowered network to get most measurements. NetMeterwill run off DeviceNet network power, even withoutbatteries installed. Remember to install batteries if youplan to use the Lock and offline viewing features.

How to Use AutoSearch ...

1. Make sure the Lock switch is in the “Run” position andturn the selector switch to AutoSearch

2. If you see - all measurements are within limits.

3. If you see or then read the display like this ...

“Switch setting <Setting #>, <MIN> or <MAX> and/or<P-P> is close to or Exceeds the spec limits.”

Then press and repeat the process for the nextbad/marginal value.To get more detail, turn theselector switch to the indicated position and use thebuttons to access related measurements.

2

1

How to use this manualThis is a reference manual for the DeviceNet NetMeter(DN-MTR). For each NetMeter switch position you willfind a page explaining the measurements available, andsuggested actions and/or remedies if your network is nothealthy.

On each page you’ll find:

The minimum shieldvoltage recordedsince the NetMeterwas plugged in orreset is -3.5V.

x1V

250

MIN

x5

Displays themaximum frame rateper second on thenetwork since theNetMeter wasplugged in or reset.

LCD display

# of times to push the advance button after movingthe selector switch to display this measurement.

DescriptionPush the Advance

button

You can view this measurement for each activedevice by pressing the or buttons.Pressing and at the same time displaysthe overall network measurement again.

The measured valueexceeds the positive ornegative input range.

No measurement taken(see additional details forspecific measurements).

Special Conditions:

Sign indicates negative over-range

/S

250

MAX K

AUTO

SEAR

CH

3

MAC

Viewing measurementfor this device (MAC ID)

Using the NetMeter

To lock measurements for offline viewing move the lockswitch to the position. To erase

Stored values are retained indefinitely, providing the lockswitch is left in the position, and the

- even if the meter is turned off.batteries are

good

stored values andrestart bus analysis move the lock switch to “Run”.

The NetMeter is reset (Min/Max and other storedmeasurements cleared) when the Lock switch is movedto the "Run" position, and when the power switch isturned On while the Lock switch is in the "Run" position.

You may reset stored measurements by either turningthe meter off and on again, or by moving the Lock switchto and back to “Run”.

Each selector switch position accesses a different busmeasurement, and each supports several differentmeasurement types.

Pressing cycles the display through the differentmeasurements available at each switch position.

Some measurements allow a detailed view for eachMAC ID. Press OR to cycle through the activeMAC IDs. Press AND together to return to theoverall network view

Display Lock

Resetting Min/Max Measurements

Viewing Measurements

LCD Display

Pushbuttons

Selector switch

Next measurement

Next MACID

Previous MACID

Return to NetworkView (push at thesame time)

4

K V

/S

%

125 250 500

1 2 3 4 5 6 7 8 9

10

11

121315 14

16

17

1 Network MAC ID (node #) or NetMeter switchsetting number (AutoSearch)

2 Display locked indicator (“lock” switch is on)

3 Measurement displayed is acceptable

4 Measurement displayed is marginal

5 Measurement displayed is unacceptable

6 Battery low - stored measurements may be lost

7 125 Kbaud network activity detected

8 250 Kbaud network activity detected

9 500 Kbaud network activity detected

10 Measurement unit is % bandwidth

11 Measurement unit is errors / messages per second

12 Measurement unit is volts

13 Measurement displayed is in thousands (kilo)

14 Measurement displayed is a maximum value

15 Measurement displayed is a minimum value

17 Displayed when viewing measurements for aparticular MAC ID. Not displayed in AutoSearchmode when the value shown in the top left corner isa switch position.

16 valuepeak-to-peakaisdisplayedMeasurement

* If none of MIN, MAX or P-P are shown then thevalue displayed is a “live” measurement, or the mostrecent “Live” measurement if the “lock” switch is on.

Display

5

Bus ErrorsNetMeter tracks network data transmission errors in real-time, and lets you know if the error rate is acceptable ,marginal , or unacceptable . Any error rate greaterthan zero is undesirable (although your network may stillfunction since CAN automatically retransmits aftererrors). An error rate greater than 10/s indicates aproblem that should be investigated.

NetMeter uses unique technology to accuratelydetermine which node was attempting to transmit when abus error occurs

Display What it means

/S

250

/S

250

MIN

250

Real-time error rateof 14 errors/second

Incremental errorcount on the entirenetwork since theNetMeter wasconnected or reset.

Maximum bus errorrate on the wholenetwork sinceNetMeter wasconnected or reset.

Minimum bus errorrate on wholenetwork sinceNetMeter wasconnected to thenetwork or reset.

2

6

x1

x2

x3

/S

250

MAX

Node error measurements only include errors known tohave occurred when the node is transmitting. Frameswith corrupt ID fields, and frames that cannot beattributed to specific nodes are not included in nodemeasurements. It is common for the sum of per-noderesults to be less than the overall network values.

A node set to the wrong baudrate causes bus errors(affecting other nodes) when it attempts to go online.

Bus Errors

What do to when you see or :

� If you suspect an intermittent cable orconnector, shake, bend or twist the suspectedcable and/or connector while watching the errorrate for changes (up or down).

� Check the other measurements and investigatethe suspect device(s) for faults consistent withthe observed symptoms.Some techniques you can use are:

� Press or to identify the device(s) withhigher error rates than other nodes. Calculatethe ratio of error rate to frame rate of suspectnodes and check for above average ratios.Devices with above average error ratios shouldbe investigated further.

Bus Errors deal withthese two wires(CANL & CANH)

�

�

Replace the device and/or cablingTemporarily remove the device from thenetwork to see of the errors cease.

2

BUS

ERRO

RS

7

Excessive cable lengths and faulty nodes cancause errors in the transmissions of some/allother nodes. Do not assume that the node(s) withthe highest error rate is faulty.

Thresholds:

Error Rate High FaultError Rate High Warn

15 /s1 /s

Bus TrafficNetMeter continuously monitors the CAN bit-stream formessage traffic. NetMeter reports Bus Traffic as eithernetwork bandwidth consumed (including bandwidthconsumed by errors/retries) or bus frames per second.

Display What it meansCurrent network ornode bandwidthutilization.

Number of messageframes per secondon the network ornode.

Maximum network ornode bandwidthrecorded sinceNetMeter wasconnected or reset.

Minimum network ornode bandwidthrecorded since theNetMeter wasplugged into thenetwork or reset.

x1

x2

x3

x4

x5

Miinimum frame rate(/S) on the networkor node since theNetMeter wasplugged in or reset.

Maximum framerate(/S) on thenetwork or nodesince the NetMeterwas plugged in orreset.

%

250

/S

250

MIN K

/S

250

MAX K

K

/S

250

%

250

MAX

%

250

MIN

3

8

Node traffic measurements include only messagestransmitted by the device except Group 2 master/slavetraffic, where ALL traffic shows up on the slave MAC ID.

Bus Traffic of 0% for a single node means that the node(MACID) has stopped communicating since theNetMeter was plugged in or reset!

�

�

�

Check the scanner configuration.Setting the scan interval (or inter-scan delay)too short can cause device timeouts due tobandwidth or node performance limitations.Setting the scan interval (or inter-scan delay) toolong reduces system performance and makesinefficient use of available bandwidth.

� Check for Change-of-State devices consumingexcessive bandwidth (look for one or morenodes with excessive bandwidth or a MAXbandwidth much higher than average)

Note about frame rate: If you know the input and outputsize (in bytes) for a polled or strobed device (see yourconfiguration or the device documentation) you candetermine the scan rate (per second) as follows:

Bus Traffic deals withthese two wires(CANL & CANH)

Scan rate =Frame Rate (from NetMeter)

Input Frames + Output Frames

Input Frames =

Output Frames =

Input Bytes 8(round up to whole number)

¸ ¸( 7 if > 8 bytes)

Output Size 8(round up to whole number, always 1frame for strobe devices)

¸ ¸( 7 if > 8 bytes)

Bus Traffic

Thresholds:

Bus Traffic High WarnBus Traffic Low Warn

90.0%10.0%

3

BUS

TRAF

FIC

9

For networks with bandwidth we suggest:

Bus PowerNetMeter continuously monitors the DeviceNet buspower quality.

Display What it means

Current network busvoltage is 17.2V.

Minimum busvoltage recordedsince NetMeter wasplugged in or reset is17.1V.

Maximum peak-to-peak (P-P) voltagerecorded sinceNetMeter wasplugged in or reset is0.6V.

Current peak-to-peak (P-P) voltage(transient or ripple)is 0.1Vp-p.

Maximum busvoltage recordedsince NetMeter wasplugged in or reset is17.4V.

x1

x4

x3

x2

V

250

V

250

MIN

V

250

MAX

V

250

P-P

V

250

MAXP-P

What’s a transient?

A transient is a short, temporary deviation of the busvoltage level.

4

Every DeviceNet network has some level of bus powertransients, which is perfectly acceptable. Transients inexcess of 2V P-P can contribute to node failures andcommunication errors in some cases and should beinvestigated. Transients in excess of 10V P-P are anindication of serious network problems..

10

Bus Power measuresvoltage levels on thesetwo wires (V+ / V-)

�

�

�

Check your power supply for proper installationand correct output voltage under load.Are your trunk/drop cables too long?Is one or more of your devices drawing toomuch current?

For bus power voltage levels we suggest:

�

�

�

Check for output devices (like contactors)powered from the network (they shouldn’t be).Check for network cables routed too close tostrong sources of interference

Check for aging network power supply withoutput ripple increasing over time

For p-p (noise) levels we suggest:

Bus PowerExamples of transients

25V

13V

Thresholds:

High Voltage FaultLow Voltage WarningLow Voltage FaultHigh P-P Voltage FaultHigh P-P Voltage Warning

25.0V14.0V13.0V10.0V2.0V

4

BUS

POW

ER

11

� If you suspect an intermittent cable orconnector, shake, bend or twist the suspectedcable and/or connector while watching the P-Pmeasurement for changes (up or down).

Shield VoltageNetMeter measures live, minimum, and maximum DCshield voltage (between shield and V-).

Display What it means

Current shieldvoltage is -3.4V.

The minimum shieldvoltage recordedsince the NetMeterwas plugged in orreset is -3.5V.

The maximum shieldvoltage recordedsince the NetMeterwas plugged in orreset is -3.2V.

x1

x2

V

250

V

250

MIN

V

250

MAX

5

12

Thresholds:

High Voltage FaultHigh Voltage WarningLow Voltage WarningLow Voltage Fault

1.0V0.3V

-4.0V-5.0V

About DeviceNet Shield Votlage

The DeviceNet specification requires that the shield andV- be connected together, and both to earth ground atthe power supply. This has the following effects:

A correctly connected shield has no current flow in itand is at the same voltage (grounded power supplyV-) throughout the system.Current flow in V- causes a voltage rise in V-Rising V- voltage causes an apparent negative shift inthe shield voltage when measured relative to V-

�

�

�

�

� Since the maximum voltage drop in V- is 5V, thenegative shift in shield voltage is between -5V and 0VSystems connected in accordance with the DeviceNetinstallation guidelines (except flat media) have a"normal" shield voltage between -5V and 0V

Shield voltagemeasures thevoltage on the shieldwire relative to V-

Shield Voltage

�

�

�

�

Make sure the Shield and V- are connected toeach other and to earth ground at the powersupply (very important)Check for shorted or open shield wiringCheck that your shield wire is actuallygrounded correctly (it’s so important you checkit twice!)The NetMeter displays “OL” if the shield is notconnected (or if the voltage is high).

For shield voltage levels we suggest:

5

SH

IELD

13

Important! Some industrial applications and some end-users employ different shield connection techniques tomeet specific requirements. In these cases the shieldvoiltage will differ from that expected in "typical"DeviceNet installations.

Semiconductor Fab Applications:Disregard or shield voltage indications ifthe shield is intentionally connected differentlythan defined in the DeviceNet Specification.

Flat Media Applications:Disregard or shield voltage indications inflat media applications as flat media has noshield. NetMeter should always display OL whenconnected to a flat media system.

Important! DeviceNet Flat Media has no shield, andshield voltage measurements are not relevant.

CAN PrimerDeviceNet is based on the CAN protocol. Afundamental understanding of CAN will help youtake full advantage of the NetMeter’s features andsignificantly improve your ability to diagnosenetwork problems quickly.

CAN messages are transmitted as a difference involtage between two separate wires, CANH(white) and CANL (blue). Differential transmissionhelps CAN and DeviceNet to operate well evenwith high levels of external interference (ie fromsources like motors, welders, etc.) Here’s whatyou might see if you captured CAN signals on anoscilloscope:

Differential receiver cancelsnoise and extracts data signal

CAN signals have two states, dominant (0) andrecessive (1). The transceiver in each DeviceNetnode determines whether a signal is a 1 or a 0based on the differential voltage between CANHand CANL.

CANH

CANL

Dominant( D )

Recessive( R )

CANH

CANL

DominantDifferential

RecessiveDifferential

14

Individual wiresinclude data + noise

Differential Signal(CANH - CANL)

CAN PrimerBecause the transceiver subtracts the CANH andCANL signals to determine the bit values, anynoise induced in the cable (the same noise isinduced in both wires) is cancelled. Transceiverchips require CANH and CANL voltages to bewithin specific limits otherwise a dominant (0)might be misinterpreted as a recessive (1) or vice-versa resulting in errors.

These out-of-range signalscould be misinterpreted

Good signal

DC common mode voltage (caused by voltagedrop in the cable, refer to page 16 and 17) is theprimary cause of the voltage shift illustratedabove. Noise induced in the data wires alsocontributes to the voltage offset.If the combination of DC common mode voltageand induced noise causes the signal voltages toexceed the transceivers capabilities, bit errors aremore likely to occur.

CANH,D

CANL,D

CANH,R

CANL,R

CANH/LDiff V, D

CANH/LDiff V, R

8

7

910

1112

0V

-5V

10V

15

Six separate CAN voltage measurements areessential to rapid troubleshooting. The NetMeteraccurately measures these voltages at thefollowing switch settings:

Common Mode VNetMeter measures the worst-case total Common ModeVoltage for your network (including DC CMV and noise).

What is Common Mode Voltage?

Common Mode Voltage is an incidental voltage that iscommon to both signal conductors in a differentialtransmission system. CMV manifests itself as an shift insignal voltage without any change in differential voltage.

Excessive CMV may cause signal voltages to exceedthe capabilities of transceiver chips, ultimately resultingin communication errors.

The primary component of CMV is voltage drop in thepower conductors. The cable resistance causes the V+voltage to drop from 24 VDC with increasing distancefrom the power supply. Similarly, the V- voltageincreases proportionally from 0VDC at the power supply.This offset results in each station having a slightlydifferent reference point (V-) which causes an apparentshift in signal voltages from each node's point of view(the signal voltages don't really change, but thedifference in V- makes it look that way).

Intermittent factors such as external interference,variations in network load current and electrical noiseinternal to nodes also contribute to CMV. Collectively,these intermittent factors are called "noise".

Total CMV is critical to network health. NetMetermeasures total CMV over time and records themaximum. To measure worst-case total CMV, leave theNetMeter connected to the network for an appropriateperiod of time (one machine cycle, one shift, one day).

Display What it means

Worst-case total CMVrecorded since theNetMeter was plugged inor reset is 3.33V.V

250

6

16

Common Mode Voltagecan not be determinedbecause there is no busactivity.

�

�

�

�

�

Check for devices that might be drawing morecurrent than you expectVerify your network design with specialattention to cable length and load currentcalculationsMove the power supply toward the middle of thenetwork, or toward the nodes that draw themost currentInvestigate adding another power supply toreduce voltage offset in V-High levels of external interference may requireyou to reduce the DC CMV limit below the 5Vrecommended in the DeviceNet Specification tokeep total CMV below 6.5V

�

�

�

NetMeter's CMV measurements are not affected bywhere on the network you take the measurement.DC CMV problems are typically caused when devicesdraw more current than expected or when cableresistance is higher than expected (too much cable)or a combination of both.CMV problems can be intermittent since few deviceshave a constant load current.

Common modevoltage deals withthese three wires(CANL, CANH,and V-)

Common Mode VThresholds:

CMV High FaultCMV High Warning

6.50V5.00V

6

CM

V

17

For CMV levels we suggest:

Notes About Common Mode Voltage (CMV)

CANH/L Diff. V (R)CANH/L differential (Recessive) shows you thedifference between CANH and CANL for recessive bits:

Why is this measurement important?

Data bits (0's and 1's) are transmitted as differences involtage between the CANH and CANL wires. Thedifferential voltage measurements are essentially ameasurement of "signal quality".

The recessive differential voltage is ideally zero, buttypically is +/- a few millivolts.

A recessive differential voltage that is not sufficientlyclose to zero may be mis-interpreted by a transceiver asa dominant bit - resulting in communication errors.

Display What it means

Current CANH/Lrecessive voltagedifferential is 0.09V.

Minimum CANH/Lrecessive voltagedifferential since theNetMeter wasplugged in or reset is0.08V.

Maximum CANH/Lrecessive voltagedifferential sinceNetMeter wasplugged in or reset is0.09V.

x1

x2

CANH/L diff. V(R) = CANHV(R) - CANLV(R)Switch 9 117

V

250

V

250

MIN

V

250

MAX

7

18

Recessive differential busvoltage can not bemeasured because thebus is stuck dominant.

�

�

�

Check for shorts and opens on the CANH andCANL wiresCheck for a missing or bad terminator (shouldbe two 120 ohm terminators from CANH toCANL - one at each end of the network)Disconnect nodes one at a time or temporarilysplit the network to check for faulty transceiversor cables.

What is “recessive?”

DeviceNet messages consist of 1’s and 0’s. Therecessive state of the bus (where the differential voltagebetween CANH and CANL is close to zero) representsthe logical value 1 (opposite from what you mightexpect). The bus is always in the recessive state exceptwhen a node is transmitting.

NetMeter measures the difference between CANH andCANL for recessive bits on the network, and if thedifference is not close to 0 volts, NetMeter indicates awarning or a fault.

CANH/L Diff. V dealswith these two wires(CANL & CANH)

CANH/L Diff. V (R)Thresholds:

Diff R Voltage High FaultDiff R Voltage Low Fault

0.08V-0.18V

7

DIF

FV

(R)

19

For CANH/L differential recessive voltagelevels we suggest:

CANH/L Diff. V (D)CANH/L differential shows you the difference betweenCANH and CANL for dominant bits:

Display What it means

Current CANH/Ldominant voltagedifferential is 1.67V.

Minimum CANH/Ldominant voltagedifferential since theNetMeter wasplugged in or reset is1.00V.

Maximum CANH/Ldominant voltagedifferential sinceNetMeter wasplugged in or reset is1.76V.

x1

x2

CANH/L diff. V(D) = CANHV(D) - CANLV(D)Switch 10 128

V

250

MAX

V

250

8

20

V

250

MIN

Dominant differential busvoltage can not bemeasured because thereis no bus activity.

Why is this measurement important?

See the description of "recessive" on page 18.

The dominant differential voltage is usually around 2V. Alesser differential voltage may be mis-interpreted by atransceiver as a recessive bit - causing bus errors.

At the beginning of each frame it is possible for severalnodes to transmit simultaneously resulting in a dominantdifferential >3V. NetMeter accurately measures dominantvoltage by sampling only when one node is transmitting.

A measured dominant differential (single nodetransmitting) larger than 3V is a clear indication of anetwork problem.

Why is this measurement important?

CANH/L Diff. V (D)Thresholds:

Diff D Voltage High FaultDiff D Voltage High WarningDiff D Voltage Low WarningDiff D Voltage Low Fault

3.00V2.75V1.45V1.20V

CANH/L Diff. V dealswith these two wires(CANL & CANH)

8

DIF

FV

(D)

21

What is “Dominant”?

DeviceNet messages consist of 1’s and 0’s. Thedominant state of the bus (where the differential voltagebetween CANH and CANL is around 2V) represents thelogical value 0 (opposite from what you might expect).The bus can only be in the dominant state when a nodeis actively transmitting.

NetMeter measures the difference between CANH andCANL for dominant bits on the network, and if thedifference is not within acceptable limits, NetMeterindicates a warning or a fault.

�

�

�

Check for shorts and opens on the CANH andCANL wiresCheck for a missing, bad, or extra terminators(should be two 120 ohm terminators fromCANH to CANL - one at each end of thenetwork !)Disconnect nodes one at a time or temporarilysplit the network to check for faulty transceiversor cables.

and no more

For CANH/L differential dominant voltagelevels we suggest:

CAN Signal ThresholdsThresholds:

SwitchCANH D Voltage High FaultCANH D Voltage High WarningCANH D Voltage Low WarningCANH D Voltage Low Fault

10.00V8.50V

-1.25V-2.25V

10

SwitchCANL D Voltage High FaultCANL D Voltage High WarningCANL D Voltage Low WarningCANL D Voltage Low Fault

7.75V6.25V

-3.50V-4.50V

12

SwitchCANH/L R Voltage High FaultCANH/L R Voltage High WarningCANH/L R Voltage Low WarningCANH/L R Voltage Low Fault

8.50V7.00V

-2.00V-3.00V

9 11

DeviceNet messages consist of 1's and 0's, which arerepresented as differences in voltage between the CANHand CANL wires. However, if the absolute voltage of thesignal (measured to the V- wire at any node) is too highor too low, bits may not be received correctly. NetMetermeasures each of the key CANH, CANL and Differentialvoltages, and if the readings are too high or low,NetMeter indicates a warning or fault.

22

Recessive bus voltage cannot be measured becausethe bus is stuck dominant.(or CAN wires are flipped)

Dominant bus voltage cannot be measured becausethere is no bus activity.

10

9 11

12

&

&

DeviceNet GlossaryBandwidth:

CANbus:

Configuration:

Determinism:

Frame Rate:

MACID:

DeviceNet, like other serial networks,supports a certain number of bits per second sent on thewire. The actual network traffic is reported as apercentage of the theoretical maximum, and is called %Bandwidth. NetMeter's measurements include bandwidthlost due to bus errors and retries but most otherdiagnostic tools only include messages inbandwidth calculations.

DeviceNet is based on a low-level networkstandard known as CAN or CANbus. Other networksthat use CAN include CANOpen and SDS. Althoughthese networks are based on CAN, physical layer andupper layer protocol differences limit the use of theNetMeter with these networks.

Because DeviceNet networks allow youto use devices in many different ways, each device mustbe configured before it will work properly on a DeviceNetnetwork. For some devices, this is as simple as setting aswitch to select the MACID (node address) and baudrate. Other devices require configuration from a PC-based software tool (Available from SST). Mostimportantly, configuration means that before you replacea device with another, identical device, you mustconfigure the replacement device properly.

Determinism is a measure of thepredictability of the performance of a system (includingbut not limited to networks). Communication errors anddelays caused by high bandwidth utilization reducedeterminism, making the system less predictable in itsoperation (less deterministic).

DeviceNet messages are sent in one ormore CAN message structures called Frames. FrameRate is the number of these structures sent in 1 second.Since one DeviceNet message may require several CANframes, the frame rate is not necessarily the same as themessage rate.

Each device on a DeviceNet network has aunique "Address", a number between 0 and 63. ThisAddress is known as the MACID or Node number.

successful

CANH

/ CAN

L

23

DeviceNet GlossaryNoise:

P-P:

Ripple:

Terminator:

Transceiver:

Transient:

An undesirable intermittent voltage on a networksignal or power wire.

Peak to peak measurements of varying voltagesignals indicate the difference between the minimum andmaximum values within a specific interval.

A regular, repeated deviation from the meanvoltage of a power or signal conductor.

1) A resistor connected at the end of atransmission line (network cable) to prevent signalreflections caused by impedance mismatches.DeviceNet requires two 120 ohm terminators, one ateach end of the network. DeviceNet terminating resistorsalso define the recessive state of the network byensuring that CANH and CANL return to zero differentialafter a dominant bit.

A transceiver is a circuit (typically a chip)that converts digital bits to/from the differential voltageson the network cable. Transceiver is a contraction of

mitter and re .

A temporary deviation from the mean voltageof a power or signal conductor.

trans ceiver

The NetMeter has twoconfiguration switches locatedin the battery compartment.

The Meter Power switch (on left)selects between bus/battery power (powered by buswhen available) and battery only power. Selectingbattery only power eliminates the possibility ofinadvertently contributing to common mode voltageproblems on extremely long networks but limits NetMeteruse to about 7 hours on fresh batteries..

The Alarm Sound switch (on right) enables and disablesthe “beep on error/transient” feature. With this featureenabled NetMeter beeps each time a bus error ortransient occurs when the selector switch is in thecorresponding position.

Switch Settings

24

AlarmSound

Meter

Bus/Battery

Battery Only

Power

Off

On

Certifications

This device complies with Part 15 of the FCC Rules.Operation is subject to the following two conditions: (1)this device may not cause harmful interference and (2)this device must accept any interference received,including interference that may cause undesiredoperation.

NOTE: This equipment has been tested and found tocomply with the limits for Class A digital device, pursuantto Part 15 of the FCC Rules. These limits are designedto provide reasonable protection against harmfulinterference when the equipment is operated in acommercial environment. This equipment generates,uses, and can radiate radio frequency energy and, if notinstalled and used in accordance with the instructionmanual, may cause harmful interference to radiocommunications. Operation of this equipment in aresidential area is likely to cause harmful interference inwhich case the user will be required to correct theinterference at his own expense.

Warning: Changes or modifications not expresslyapproved by SST, a division of Woodhead Canada,could void the user's authority to operate the equipment.

This Class (A) digital apparatus complies with CanadianICES-003.

FCC

Industry Canada

This device meets or exceeds the requirements of thefollowing standard(s):

UL3111-1 Can/CSA C22.2

CAT II 30V

25

LISTED

MEASURINGAND

TESTING EQUIPMENT

1WA4

CertificationsMarking of this equipment with the symbol CEindicates compliance with European CouncilDirective 89/336/EEC - The EMC Directive asamended by 92/31/EEC and 93/68/EEC.

To maintain compliance with the limits andrequirements of the EMC Directive it is required to usequality interfacing cables and connectors whenconnecting this device. Refer to the cable specificationsin the Hardware Guide for selection of cable types.

This device meets or exceeds the requirements of thefollowing standard:

EN 61326:1997 including amendment A1:1998 -"Electrical equipment for measurement, control andlaboratory use - EMC requirements.”

This is a Class A product. In a domestic environment thisproduct may cause radio interference in which case theuser may be required to take adequate measures.

This equipment is neither designed for, nor intended foroperation in installations where it is subject to hazardousvoltages and/or hazardous currents.

Note:

Warning!

Caution!

CablesThe NetMeter is designed for use with the suppliedcables or the following Brad Harrison replacementcables:

DND-21A-M010 DND-22A-M010

26

Information & Support

Warranty

Care & Cleaning

For more information or technical support for theNetMeter for DeviceNet or any other NetAlert product,please contact your local Woodhead ConnectivityDistributor or one of our offices below:

SST/Woodhead Connectivity guarantees that all newproducts are free from defects in material andworkmanship when applied in the manner for which theywere intended and according to SST’s publishedinformation on proper installation. The Warranty periodfor the NetAlert NetMeter for Devicenet is one year fromthe date of shipment.

SST/Woodhead Connectivity will repair or replace, at ouroption, all products returned freight prepaid, which proveupon examination to be within the Warranty definitionsand time period.

The Warranty does not cover costs of installation,removal, or damage to user property or any contingentexpenses or consequential damages. Maximum liabilityof SST/Woodhead Connectivity is the cost of theproduct(s).

If your NetMeter requires cleaning we recommend usingonly a soft dry cloth. Solvents or water may enter theenclosure with undesirable consequences.

SST division of Woodhead Canada LimitedToll free: 877-427-0850Direct: 519-725-5136Email: Sales@myNetAlert.com

TechSupport@myNetAlert.com

Woodhead LPToll free: 877-427-0850Direct: 847-272-7990

Woodhead Canada LimitedDirect: 905-624-6518

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Copyright © 2002 SST, a division of Woodhead Canada Limited

All rights reserved. No portion of this document may be reproduced inany form without the prior written permission of Woodhead CanadaLimited.

NetAlert, NetMeter and SST are trademarks of Woodhead Industries,Inc. All other trade names are trademarks or registered trademarks oftheir respective companies.

SST strives to ensure accuracy in our documentation. However, due torapidly evolving products, on occasion software or hardware changesmay not have been reflected in the documentation. If you notice anyinaccuracies, please contact us.

Publication Revision: 1.2Publication Date: February, 2002

SST, part of Woodhead Connectivity50 Northland Road, Waterloo, OntarioCanada N2V 1N3 Tel (519) 725-5136www.myNetAlert.comwww.mySST.comwww.woodheadconnectivity.com

Document Info

SpecificationsEnvironment

Bus Power Voltage Measurement

Maximum Limits

Power Supply

Shield Voltage Measurement

CAN Voltage Measurement

Storage Temperature

Range

Voltage between any two terminals

Network Power

Battery Power

Range

Range

-40ºC to 85ºC

2V to 26V & reverse polarity

2 X AA Alkaline Batteries

60mA @ 11Vdc to 30Vdc

-10V to 1V

-5.25V to 9.98V

Operating Temperature

Calibrated Accuracy (DC)

Calibrated Accuracy

Calibrated Accuracy (signal)

0ºC to 40ºC

±30Vdc

0.5% ±1 count

0.5% ±1 count

0.5% ±2 counts±20mV

Humidity 5% to 90% (non-condensing)

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Calibrated Accuracy (diff.) 1.0% ±4 counts±20mV

Calibrated Accuracy (P-P) 1.0% ±2 counts