Page 1: Table Of Contents
User Manual ControlNet NetChecker Catalog Number 1788-CNCHKR Topic Page Important User Information European Communities (EC) Directive Compliance Additional Resources Product Overview Diagnostic Mode Bargraph Mode Operation Reporting Examples Additional Tips Waveform Examples...
Page 2: Important User Information
In no event will Rockwell Automation, Inc. be responsible or liable for indirect or consequential damages resulting from the use or application of this equipment.
Page 3: European Communities (Ec) Directive Compliance
Additional Resources These documents contain additional information concerning related products from Rockwell Automation. Resource Description Industrial Automation Wiring and Grounding Provides general guidelines for installing a Rockwell Automation industrial Guidelines, publication 1770-4.1 system. Product Certifications website, http://www.ab.com Provides declarations of conformity, certificates, and other certification details.
Page 4: Product Overview
The NetChecker is designed to be connected to a network via either a standard tap or the provided BNC T and cable. The NetChecker is a passive instrument. It does not send any signal on the network under test. Rockwell Automation Publication 1788-UM001B-EN-P - August 2012...
Page 5 Node On Line Power Switch Push ON Slow Edges Node Finder Input Illegal Framing Jack Poor Signal Quality Pass/Fail Push ON Buzzer Power 5VDC 0.25A ControlNet NetChecker Rockwell Automation Allen-Bradley Left 1788-CNCHKR ControlNet NetChecker Right Rockwell Automation Publication 1788-UM001B-EN-P - August 2012...
Page 6 • ENV 50204, Radiated immunity from digital radio • IEC 1000-4-2, ESD susceptibility • IEC 1000-4-3, Radiated immunity • IEC 1000-4-4, EFT/B immunity • IEC 1000-4-6, conducted RF immunity Rockwell Automation Publication 1788-UM001B-EN-P - August 2012...
Page 7: Diagnostic Mode
“0” and ignored. Note that this sensitivity range is deliberately set above the absolute minimum peak-to-peak voltage required by the ControlNet specification (510mVpp). The M (medium) and H (high) positions provide higher voltage references and less sensitivity as shown in the table above. Rockwell Automation Publication 1788-UM001B-EN-P - August 2012...
Page 8 (rapidly flashing red and green) if the messages received from this node exhibit one or more of the faults signaled by the fault status indicators. Rockwell Automation Publication 1788-UM001B-EN-P - August 2012...
Page 9: Bargraph Mode
In Bargraph mode, the Poor Signal Quality and Illegal Framing detections are performed with the threshold defaulted to M (medium). If Poor Signal Quality or Illegal Framing are detected, they are signalled only by the buzzer. The Slow Edges detection is not performed in Bargraph mode. Rockwell Automation Publication 1788-UM001B-EN-P - August 2012...
Page 10 Node Finder thumbwheels to 00. The NetChecker will display two green status indicators, indicating the strongest and the weakest levels encountered on the network. The maximum and the minimum levels indicated remain latched until NetChecker power is cycled. Rockwell Automation Publication 1788-UM001B-EN-P - August 2012...
Page 11: Operation
SW2 are not active in the external power mode; however, it is better to leave SW1 in the OFF position). ATTENTION: Make sure that your adapter is CE compliant and that the system formed by the NetChecker plus the adapter is also CE compliant. Rockwell Automation Publication 1788-UM001B-EN-P - August 2012...
Page 12 Recognize, however, that you are removing a node from the network. Test that node later from a different location on the network. Rockwell Automation Publication 1788-UM001B-EN-P - August 2012...
Page 13 L, M, H Fault All Off Buzzer Does not sound Bargraph indication Within range of 2…6 Refer to the table in the following section to determine the overall state of your network. Rockwell Automation Publication 1788-UM001B-EN-P - August 2012...
Page 14 Remember that the purpose of the NetChecker is to alert for possible problems with network cabling and that its sensitivity is greater than required by the ControlNet specification. Rockwell Automation Publication 1788-UM001B-EN-P - August 2012...
Page 15 ControlNet specification. Check for possible high signal attenuation caused by inadequate coaxial media used for the trunk cable or segments. High resistance at the contact points of the BNC connectors on the trunk cable may also add abnormal signal attenuation. Rockwell Automation Publication 1788-UM001B-EN-P - August 2012...
Page 16 Slow Edges has the following indications. Status Indicator State TRAFFIC Green Slow edges Blinking red Illegal Framing May also be blinking red Poor signal Quality May also be blinking red Pass/Fail Yellow or red Buzzer Sounds Rockwell Automation Publication 1788-UM001B-EN-P - August 2012...
Page 17: Reporting Examples
BNC connector. The status indicator Node On Line is Off because there is no node at address 11. Rockwell Automation Publication 1788-UM001B-EN-P - August 2012...
Page 18 Generally, the bargraph displays two green status indicators indicating the maximum and the minimum level of signal seen at the point of test on the network. Normally, these should be in the range of status indicators 2…6. Rockwell Automation Publication 1788-UM001B-EN-P - August 2012...
Page 19 If status indicator 7 (top of the scale) turns red, a level of signal greater than 9.5Vpp was detected. This may indicate a strong mismatch on the network. Check if terminations are present. Rockwell Automation Publication 1788-UM001B-EN-P - August 2012...
Page 20: Additional Tips
The NetChecker will signal immediately any degradation of the signal quality at the media level even if the network is still performing correctly. The NetChecker should be set in Diagnostic mode. Rockwell Automation Publication 1788-UM001B-EN-P - August 2012...
Page 21: Waveform Examples
Transmit Level: 8.2Vpp +/-1.3V Tx Off One Bit Time 200nS Waveform on Cable Ideal Received Packet on ControlNet Network (as seen at receiving node) 100nS 510mVpp min. 0 Volt 40nS max jitter Receive Mask Rockwell Automation Publication 1788-UM001B-EN-P - August 2012...
Page 22 22 ControlNet NetChecker Typical Waveforms Good Signal Small Amount of Reflection Remote Station 6.000 V/D 100 nS/D Example of Waveform Seen When Network Is Improperly Terminated 2.000 V/D 500 ns/DIV Rockwell Automation Publication 1788-UM001B-EN-P - August 2012...
Page 23 Excessive attenuation causes loss of signal: • Poor quality coaxial cable – Resistance too high – Losses in dielectric • Overloaded network – Too long trunk segment – Excessive number of nodes per segment • Impedance mismatches Rockwell Automation Publication 1788-UM001B-EN-P - August 2012...
Page 24 Rockwell Automation representative. New Product Satisfaction Return Rockwell Automation tests all of its products to ensure that they are fully operational when shipped from the manufacturing facility. However, if your product is not functioning and needs to be returned, follow these procedures.

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