# Channel Operation Testing

The general channel operations test procedure is as follows:

- Do whatever is most practical to create violation conditions on each channel.
- Verify that the correct calls are made and reports are clear.

The troubleshooting tools available include:

- Enter key code 3 Z to verify messages for channel Z are clear and make sense.
- Enter key code 5 * Z to get configuration report for channel Z.
- Enter key code 95 to get a configuration report for all non-disabled channels
- Enter key code 916 Z to read a count of problems for that channel. You may need to clear this count to see if problems are spurious or persistent (use 916 Z**).

Note: Occasional communication errors are to be expected. Frequent occurrence or conditions that persist through trip delay periods indicate problems.

Symptoms of channel operation problems include:

- A communication alarm occurs.
- Net address configuration reports an error code.
- Any violation condition goes unreported.

The most common causes of PLC operation problems are:

- A network connection problem exists.
- Scanning on the network has been disabled.
- Communication alarm or other trip delays are too long (no alarms), or too short (too many communication alarms).
- The channel is not configured for violation conditions.
- Set points or other violation conditions are not correct.

Network scan time (related to latency) is longer than the application assumed. From Alarmware™ with the RTU online, choose menu item Diagnostics, and select "Net Diagnostics Summary Report". In the resulting report, scroll to read the Net 1 scan time within the section of the report for Net 1. Or, use key code 902 11 to determine the PLC network scan time. Then under Configuration | Devices, select the Protocol tab and enter an appropriate Communication Alarm Delay. An entry of twice the reported scan time is a good starting value. Note that network scan time is strongly affected by the number of active channels being scanned. Therefore you can get the best reading of scan time and make the best determination of an optimum Com Alarm Delay to set, after the basic configuration of the RTU has been done.

Other RTU configuration parameters, such as phone numbers, trip delays, or Destination Channel Groupings, are not correct.