The PMC K/L/M/P Programming Manual defines all the Symbols, but basically a Keep Relay can be displayed as a Coil (circle on the RH side of the network) or as a Normally Open or Normally Closed contact (similar to a switch). The Keep Relay will have an address (Dnnn.n) that identifies the Keep Relay. For example, you may see something like D350.3 next to the coil or contact.
However, you really don't need to look at the ladder display if the MTB has provided you with a specific Diagnostic bit.
In order to change a Diagnostics bit, you need to do the following:
1. Go to MDI mode
2. Set the Program Protect keyswitch to enable program editing
3. Set Parameter Write Enable = 1 on the upper CNC Parameter page.
4. Go to the Diagnostics page and page down (or search) to the desired diagnostic address (e.g. 0350).
4. Enter the new value and press the INPUT key.
5. Go back to the CNC Parameter page and set the Parameter Write Enable = 0
Note: You'll get a message 100 displayed after step 3, but it is normal.