Comtech EF Data CRS-311 - Manual (Page 153)

CRS-311 1:1 Redundancy Switch Revision 7
Appendix A MN/CRS311.IOM
A-9
A.3.4 EIA-485 Null Modem Cable (DB-9M to DB-9M)
Use this EIA‐485 Null Modem Cable (Figure A‐7) with CDM‐Qx/QxL modems: At the CRS‐311 end, attach this cable to the DB‐9F “485 Pass‐
through” connector on the CRS‐230 System Controller Module. At the modem end, attach this cable either to the optional EIA‐485 Multi‐Drop
Ribbon Cable (CEFD P/N CA‐0000095, Figure A‐4) or to the standard EIA‐485 Multi‐Drop Shielded Cable (CEFD P/N CA‐0000096, Figure A‐5).
Figure A-7. EIA-485 Null Modem Cable (CEFD P/N CA/WR11419-1)