# Self-Test on Network

Response to the self-test on a network will either be with Normal... or with the Error Code. All available network diagnostic counters and information will be reset. If a LDL device is configured, additional information will be printed.

Modbus Note: During self-test, communication alarms may trip, but these alarms will be reset after exiting program mode.

Keycode Examples: (Applicable for Modbus)

- To do a Self-Test on the NET 1 PLC, press: 90212 ENTER.

Keycode Examples: (Applicable for ModbusTCP or EtherNet/IP)

The communication health bit is configured with a special logic to monitor network health of connecting PLCs – If Ethernet master loses connection, a health byte in address 40125 will go from 0 to 256 or a bit in address 01992 will go from 0 to 1 indicating that the communication with the network is impaired and if the Catalyst is programmed to look for this change. A bit flipping from 0 to 1 can report the loss of communication via an alarm to the users.

To program the loss of communication alarm follow the instructions in the main Catalyst manual and ensure that the register name space is set accordingly.

Program 4532 * 2 * 2 * 01992 * (channel 32 reads address 01992) and 4532 2 (normally 0, alarm on 1).

Note that Normal means actually talking to the PLC. You would get an alarm if you are plugged into the Ethernet, but the PLC is not communicating, or if you are not plugged into the Ethernet.

Alarmware™ Example:

- To do a Self-Test on a Network, connect to the desired RTU and click Diagnostics on the main menu.
- Select the Network Diagnostics Self-Test menu item.
- Review the results in the "Messages for RTU" window.