Appendix G. Short-Haul Modems
NOTE With short-haul modems it is necessary to configure the base station RF400’s “RS-232 Auto Power Down Enable” (in the Advanced Setup \ Interface Parameters menu) to mode "0" which will maintain the radio's RS-232 port always active. This results in an additional constant 2 mA current drain by the RF400. If you don’t do this, the base RF400’s RS-232 port will turn off 30 seconds after activity and the attached SRM-5A which gets its power from the port will not receive any messages from the PC.
G-2