
1-5
1 Introduction
CJ-series Serial Communications Units Operation Manual for NJ-series CPU Unit(W494)
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Protocol Overview
A Serial Communications Unit is a CPU Bus Unit that provides RS-232C or RS-422A/485 serial com-
munications ports. You can use the following five serial communications modes as required for each
serial communications port.
•
Protocol Macro: For communications between PLCs and general-purpose external devices
•
Serial Gateway
•
No-protocol
•
Modbus-RTU Slave
•
Loopback Test: For testing the communications ports
The Serial Gateway can also be executed in Protocol Macro Mode.
Modbus-ASCII Slave Mode is not supported.
A connection example for each serial communications mode is shown in the following sections for a
Serial Communications Unit.
Product
Model
number
Serial ports
Serial communications mode
Protocol
Macro
Loopback
Test
Serial
Gateway
Serial
Gateway in
Protocol
Macro Mode
No-protocol
Modbus-
RTU Slave
Serial Com-
munications
Unit
CJ1W-
SCU22
RS-232C
OK
OK
OK
OK
OK
OK
RS-232C
OK
OK
OK
OK
OK
OK
CJ1W-
SCU32
RS-422A/485
OK
OK
OK
OK
OK
OK
RS-422A/485
OK
OK
OK
OK
OK
OK
CJ1W-
SCU42
RS-422A/485
OK
OK
OK
OK
OK
OK
RS-232C
OK
OK
OK
OK
OK
OK
Device to be connected
General-pur-
pose exter-
nal device
None
Depends on the protocol
used at the conversion des-
tination
General-pur-
pose exter-
nal device
Host Link
computer
Содержание CJ1W-SCU22
Страница 192: ...4 Using Protocol Macros 4 56 CJ series Serial Communications Units Operation Manual for NJ series CPU Unit W494...
Страница 250: ...6 No protocol Mode 6 22 CJ series Serial Communications Units Operation Manual for NJ series CPU Unit W494...
Страница 460: ...A Standard System Protocol R 126 CJ series Serial Communications Units Operation Manual for NJ series CPU Unit W494...
Страница 473: ...Index 1 CJ series Serial Communications Units Operation Manual for NJ series CPU Unit W494 I Index...