16
CTI 2557-A Installation and Operation Guide
Figure 16 Cable Grounding
2.7
Checking Module Operation
First turn on the base supply power. If the module diagnostics detect no problems, the status indicator
on the front of the module will light. If the status indicator does not light, blinks, (or goes out during
operation), the module has detected a failure. For information on viewing failed module status, refer to
your SIMATIC® TISOFT user manual. To diagnose and correct a module failure, refer to the next
section on troubleshooting.
You must also check that the module is configured in the memory of the PLC. This is important
because the module will appear to be functioning regardless of whether it is communicating with the
PLC. To view the PLC memory configuration chart listing all slots on the base and the inputs or
outputs associated with each slot, refer to your SIMATIC® or TISOFT Programming Manual. An
example chart is shown in the following figure.
NOTE:
The 2557-A is isolated channel group to channel group. Each group consist of 2 input channels.
Shields within a channel group may be terminated together at either G terminal. CTI
recommends that the shield wire be soldered or crimped to the wire connected to the G
terminal.
