Mitsubishi Melsec-A (Serial RS232) ID:21

Interface Description

IGSS32 offers a serial interface for the Mitsubishi Melsec A/AnS type PLC equipment. The Melsec-A communications protocol enables Mitsubishi PLCs to communicate with external devices such as computers running IGSS32, printers, CRTs etc using RS-232C and RS-422 serial interfaces.

An AJ71C24 or compatible interface board must be installed in the Melsec-A/AnS PLCs in order make a point-to-point connection. The point-to-point connection can be extended to a multidrop network by connecting two or more PLCs.

The communication interface supports both direct and dialled-up connections.

The IGSS32 system polls the PLC equipment cyclically according to one of four user-defined time intervals. The time intervals are configurable from 100 milliseconds to 999 seconds. The system automatically groups process data in data blocks – thus fully exploiting the the communication link in relation to the present configuration.

NOTE: The IGSS32 serial interface driver is compatible with the TCP/IP based Ethernet driver for Mitsubishi Melsec-A/AnS PLCs. This means that no changes has to be made.

Technical Data

Electrical Interface : RS232
Protocol : Mitsubishi Melsec-A format 1 protocol
Types of data : String, Fixed point 8, 16, 32, BCD 16, 32.
PLC types supported : All Mitsubishi PLCs types supporting the AJ71C24 (or compatible) interface board. E.g. A1-, A2-, A3-, AnS etc. type CPUs.
Addressing : Node (PLC), data type (D, R, T, C and expanded D areas), Area index, bit offset (a whole number of words is read or written)
Supported platforms : Windows Vista, Windows XP, Windows 2003 Server, Windows 2000 .
Max. telegram size : Up to 512 bytes pr. Telegram depending of capacity of AJ71C24 or compatible module.
Transmission speed : Up to 115Kbaud depending on the AJ71C24 (or compatible module) port speed.
Throughput : Up til 4 telegrams pr. Channel pr. Second (depending on available bandwidth).
Max. number of channels : Up to 8 COM ports are supported concurrently.
Max. number of nodes : 32 pr. COM port
PC hardware requirements : 1-8 standard serial ports (COM ports). Standard modem(s) if dialled-up is used.
PC software requirements : None