Comtech EF Data CRS-100 Operation Manual page 30

Connector Pinouts
For correct operation of the CRS-100, the Modems must have the
following Firmware versions installed:
CDM-500 - Version 1.18 or later
CDM-550 - Version 1.10 or later
CDM-550T - Version 1.04 or later
IMPORTANT
If the modems do not meet this requirement, please contact the factory
to arrange for a free upgrade to be sent to you.
5–2
CRS-100 1:1 Redundancy Switch
Rev. 1.2