Symmetricom 1000 User Manual

Chapter 6 Maintaining and Troubleshooting the TimeProvider

Replacing the Only IOC 
To replace the only IOC in a shelf, use the following procedure. Output signals will 
resume once the IOC has achieved lock on an input signal. This procedure 
assumes that you have stored the contents of the IOC memory in the IMC using the 
CPY-MEM command.

1. Attach a wrist grounding strap and connect it to the TimeProvider chassis.

2. Install the IOC into the shelf and tighten the captive retaining screws.

3. Copy the contents of the IOC memory stored in the IMC by issuing the following 

command.

CPY-MEM:::::IMC,IOC,IOC;

This command may take more than two seconds to execute; if it does, then the 
In-Process response is issued. See the TimeProvider TL1 Reference Guide for 
more information on the CPY-MEM command.

If you have not stored the contents of the IOC memory in the IMC, then provision 
the IOC using the procedures and commands described in 

4. Wait for the IOC to reboot and qualify the reference inputs.

Replacing a Redundant IOC
To replace either of two IOCs in a shelf, use the following procedure. Output signals 
will not be affected by this procedure. You can also use this procedure to add an 
IOC to a shelf that has only one IOC.

1. Install the IOC into the shelf and tighten the captive retaining screws.

2. Wait for the IOC to reboot and qualify the reference inputs. During this time the 

Active IOC updates the new IOC’s memory with current values.

Replacing Both IOCs
Use this procedure to replace both IOCs in a shelf. Output signals will resume when 
the Active IOC has warmed up and qualified the reference signals. This procedure 
assumes that you have stored the contents of the IOC memory in the IMC using the 
CPY-MEM command.

1. Attach a wrist grounding strap and connect it to the TimeProvider chassis.

2. Install the IOC into the left slot of the shelf and tighten the captive retaining 

screws. This IOC will become the Active IOC.

3. Wait for the IOC to reboot.