Nortec Industries NHTC Series Troubleshooting Communication Problems, 10-30, Page, Solution

Table 3. Troubleshooting Communication Problems

Problem

1.The BMS network cannot read/write any information to any of the networked humidifiers

2.The BMS network can see some of the networked humidifiers but not others.

3.The BMS network receives information from the networked humidifier(s) but the information is mismatched or the humidifier responds un-expectedly

4.After sending the humidifier a network-based demand signal the unit powers down after several minutes. The nviNetSensor variable is switched on and a value has been set for the nviRHDem1 variable.

Solution

Verify that the network connection is made and is connected properly.

Verify that the correct network settings are being used. The LINKS 2 module may need to be restarted to load the new settings.

Check the Serial Port Activity LED on the Nortec OnLine module to ensure proper communication with the humidifiers. Data is first received from the humidifier to the OnLine module. The OnLine module then transmits this data, via the Ethernet port, to the LINKS 2 module.

Check the Ethernet port activity on the LINKS 2 module to ensure it is receiving data from the Nortec OnLine module.

Check the transmit and receive status LEDs to determine if there is any network traffic being sent or being received by the LINKS 2 module from the BMS network

Verify proper connections to networked humidifiers.

Turn the LINKS 2 module and the OnLine module off for several seconds then switch it back on to reload the control program. Allow for some time for the network variables to be polled.

Ensure network variables are mapped correctly to the BMS.

Ensure proper connections to the humidifiers.

Disconnect all of the humidifiers from the LINKS 2 package except for the unit that is not responding to the network. Turn the LINKS 2 package off and then back on. Check if the humidifier can now be seen by the BMS

Verify that the network variables have been mapped to the BMS network correctly. It is possible that the variables have been cross-linked during the network integration process.

Connect humidifiers one at a time and test units individually.

When a BMS network demand/RH signal is being used the network must refresh the nviRHDem signal at least every 5 minutes otherwise the humidifier will revert to a 0 demand state. This is a safety precaution in case the BMS network connection is lost.

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Page 6 2008-02-18