Cyclades AlterPath ACS, Command Reference Manual

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ACS1-only Cabling Information
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C.4 ACS1-only Cabling Information
ACS1 Connectors
ACS1-only Cabling Information
The RS-485 Standard
The RS-485 is another standard for serial communication and is available only in the
ACS1. Different from the RS-232, the RS-485 uses fewer wires - either two wires (one
twisted pair) for half duplex communication or four wires (two twisted pairs) for full
duplex communication. Another RS-485 characteristic is the “termination.” In a
network that uses the RS-485 standard, the equipment is connected one to the other in a
cascade arrangement. A “termination” is required from the last equipment to set the end
of this network.
ACS1 Connectors
Although the RS-485 can be provided in different kinds of connectors, the ACS1 uses a
9-pin D-shaped connector (DB-9) and a Terminal Block with the pin assignment
described below.
RS-485 Signal Name/Function Terminal Block pins
Chassis Not in use 1
TXA- Transmit Data - (A) 2
TXB+ Transmit Data + (B) 3
RXA- Receive Data - (A) 4
RXB Receive Data + (B) 5
Chassis Not in use 6
Table C.16: RS-485 Pinout for the ACS1 - Connector pin assignment