Yokogawa µR20000 - Manual (Page 29)

3-1
IM 04P01B01-17E
Using
the
RS-422A/485
Communication
Interface
(/C3
Option)
1
2
3
4
5
6
App
Index
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
specifications
Complies with the EIA-422A(RS-422A) and
EIA-485(RS-485) standards
Connection Multidrop Four-wire system
Two-wire system 1:32
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)