Comtech EF Data SMS-458B - Manual (Page 62)

SMS-458B Modem Protection Switch Revision 2
Theory of Operation MN/SMS458B.IOM
4–2
Figure 4-1. Monitor and Control
4.1.2 Description of Options
4.1.2.1 M&C Serial Interface
The M&C communicates with the address decoder/driver through an EIA-232 interface.
Set the M&C for EIA-232 operation as follows:
1. Remove JP1, JP2, and JP3.
2. Install JP4, JP5, and JPX.
3. Install JP7 at EIA-232 location.