2. HOST COMMUNICATION
IMR02F04-E1
3
Modbus
Interface:
Based on RS-485, EIA standard
Based on RS-422A, EIA standard
Connection method:
RS-485:
2-wire system, half-duplex multi-drop connection
RS-422A: 4-wire system, half-duplex multi-drop connection
Synchronous method:
Start-stop synchronous type
Communication speed:
1200 bps, 2400 bps, 4800 bps, 9600 bps, 19200 bps, 38400 bps
Data bit configuration:
Start
bit:
1
Data bit: 8
Parity bit: Without, Odd or Even
Stop bit: 1 or 2
Protocol:
Modbus
Signal transmission mode:
Remote Terminal Unit (RTU) mode
Function code:
03H (Read holding registers)
06H (Preset single register)
08H (Diagnostics: loopback test)
10H (Preset multiple registers)
Error check method:
CRC-16
Error code:
1: Function code error
2: When the mismatched address is specified
3: When the specified number of data items in the query message
exceeds the maximum number of data items available
4: Self-diagnostic error response
Termination resistor:
Externally terminal connected (Example: 120
1/2 W)
Maximum connections:
Up to 31 indicators
Interval time:
0 to 250 ms
Data interval extension time:
0 to 250 ms
Signal logic:
RS-485, RS-422A
Signal voltage
Logic
V (A)
V (B)
2 V
0 (SPACE)
V (A)
V (B)
2 V
1 (MARK)
Voltage between V (A) and V (B) is the voltage of (A)
terminal for the (B) terminal.
Data mapping:
When this communication method is used, 16 types of data (mapping
data) can be specified as desired for the specified indicator, and
read/write can be performed continuously.
