Serial Link
 
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Description
Serial link is a communication protocol in which the serial port can be configured as RS485 or RS232 by Control Expert. The serial link is used for connecting the HMI, modem, and other serial devices.
The following table describes the characteristics of the serial communication channels:
Characteristic
Description
Protocols supported
  • Modbus protocol (RTU and ASCII)
  • Character mode protocol
Connection
Shielded RJ45 connector
Physical link
  • RS485 non-insulated serial link
  • RS232 non-insulated serial link
The following table shows the specification of Modbus link:
Characteristic
Description
Value
Serial link physical spec.
Baud Rate
300…19,200 bps
Connector type
Shielded RJ45
Interface
RS232, RS485 software configurable
Connection Media
2-wire RS485
RS232 with or without RTS, CTS handshaking signals.
Mode of Operation
Master/Slave
Polarization
Software configurable polarization on RS485 in character mode.
RS232 type
DTE
5 Vdc output power
Voltage tolerance: ±10%
Maximum current: 190 mA
Max. cable length
RS232: 15 m
RS485:
  • 10 m non-isolated link
  • 1,000 m isolated link
(For an isolated link, the TWD XCA ISO isolation box must be used.)
The following figure shows the LED indicator of the Serial Communication:
The following table lists the definition of the LED indicator:
Label
Color
Description
SER COM
Yellow
Indicates the communication activity of serial link
The following table describes the LED pattern and the indication:
LED
Pattern
Indication
SER COM (yellow): serial data status
flashing
Data exchange on the serial connection is in progress (receiving or sending)
off
No data exchange on the serial connection
Representation
The following figure shows the RJ45 serial port:
The below table lists the pin assignment of RJ45 connector:
RJ45 Pin No.
RS232 Signal Name
RS485 Signal Name
1
RXD
Reserved
2
TXD
Reserved
3
RTS
Reserved
4
Reserved
D1
5
Reserved
D0
6
CTS
Reserved
7
5 V output
5 V output
8
GND
GND
NOTE: The RS232 4-wire, RS485 2-wire, and power supply cables all use the same RJ45 connectors. MC80 PLC can use TWDXCAISO module as an isolation solution.