3-1
IM 04P01B01-17E
3
Using the RS-422A/485 Communication Interface (/C3 Option)
3.1
RS-422A/485 Communication Interface
Specifications
This section describes the RS-422A/485 communication interface specifications.
Item
Specifications
Terminal block type
Number of terminals: 6, terminal attachment screws: ISO
M4/nominal length of 6 mm
Electrical and mechanical
Complies with the EIA-422A(RS-422A) and
specifications
EIA-485(RS-485) standards
Connection
Multidrop Four-wire system
1:32
Two-wire system
1:31 (Modbus slave protocol)
Transmission mode
Half-duplex
Synchronization
Start-stop synchronization
Baud rate
Select from 1200, 2400, 4800, 9600, 19200, and 38400 [bps].
Start bit
Fixed to 1 bit
Data length
Select 7 or 8 bits
Parity
Select Odd, Even, or None (no parity).
Stop bit
Fixed to 1 bit
Received buffer length
2047 bytes
Escape sequence
Open and close
Electrical characteristics
6 points consisting of FG, SG, SDB, SDA, RDB, and RDA
The SG, SDB, SDA, RDB, and RDA terminals and the
internal circuitry of the recorder are functionally isolated.
The FG terminal is the frame ground.
Communication distance
Up to 1.2 km
Terminal resistance
120
Ω
, 1/2 W
Chapter 3 Using the RS-422A/485 Communication Interface (/C3 Option)
