Seco Smarc CSM-B79 User Manual page 65

COM0_RTS#/COM2_RTS#: COM port #0 / #2 RS-232 Request to Send handshaking signal
COM0_CTS#/COM2_CTS#: COM port #0 / #2 RS-232 Clear To Send handshaking signal
COM0_Rx+/COM0_Rx-: COM port #0 RS-422 Receive differential pair
COM0_Tx+/COM0_Tx-: COM port #0 RS-422 Transmit differential pair
COM2_Rx+/COM2_Rx-: COM port #2 Full Duplex RS-485 (RS-422) Receive differential pair
COM2_Tx+/COM2_Tx-: COM port #2 Full Duplex RS-485 (RS-422) Transmit differential pair
COM0_Data+/COM0_Data-: COM Port #0 Half Duplex RS-485 Differential Pair
COM2_Data+/COM2_Data-: COM Port #2 Half Duplex RS-485 Differential Pair
Other two 3-way jumpers, CN63 and CN64, can be used to place 120Ohm terminations between the differential pairs of COM0 and COM2 when working in RS-
422/RS-485 modes.
CN63 position
1-2
2-3
Not inserted
SER#1 serial port, instead, is carried to the feature connector (see par.3.3.26) or used to manage the micro-B USB connector for Debug (see par.3.3.20), depending
on the SER#1 redirector dual DIP switch SW7 (see par.3.3.20).
SER#3 serial port, instead, is carried directly from card edge connector to the feature connector (see par.3.3.26)
CSM-B79
CSM-B79 User Manual - Rev. First Edition: 1.0 - Last Edition: 1.1 - Author: A.R - Reviewed by S.R. - Copyright © 2021 SECO S.p.A.
COM Port #0 termination
120Ohm on Data differential pairs (RS-485 mode)
No terminations
-422 mode)
CN64 position COM Port #2 termination
1-2 120Ohm on Data differential pairs (RS-485 mode)
2-3 No terminations
Not inserted -422 mode)
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