Pre-Mapped Symbol Interface (Pmsi) Connector (Db-9F); Table 3-12. Pmsi Connector Pinouts - Comtech EF Data CDM-425 Installation And Operation Manual

3.2.3.3

Pre-Mapped Symbol Interface (PMSI) Connector (DB-9F)

Rear Panel Connectors and Pinouts
The Pre-Mapped Symbol Interface (PMSI) is a 9-pin Type 'D' female
connector. The PMSI is an EIA-485 multidrop bus system, used in tandem
with Carrier-in-Carrier (CnC), where one device transmits, and all other
devices on the multidrop bus are configured to receive.

Table 3-12. PMSI Connector Pinouts

(R>L)
Description
Pin #
5
PMSI MSB – EIA-485 (+)
9
PMSI MSB – EIA-485 (–)
4
PMSI LSB – EIA-485 (+)
8
PMSI LSB – EIA-485 (–)
3
PMSI symbol clock – EIA-485 (+)
7
PMSI symbol clock – EIA-485 (–)
2
Spare (No connection)
6
Spare (No connection)
1
Ground
CDM-425 Advanced Satellite Modem
Direction
In/Out
In/Out
In/Out
In/Out
In/Out
In/Out
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MN-CDM-425