Mitsubishi PLC analog input address


Thread Starter



I have to write a new HMI program for a Mitsubishi A3ACPU PLC which is in use. I use an OPC server to connect to the PLC. I want to access the analog inputs of the PLC.
The analog input cards are of type A616AD. On a drawing that I am provided for the PLC, I see the following information on an analog card: X140~X14F X150~X15F. As far as I understand there are 16 analog input channels on this type of card.

What are the addresses of the analog input values on this card then? I mean how to declare the tag addresses in the OPC Server. Are they X140, X142, X144, …?

I need this urgently. Please advise! Thank you.
I don't have much experience with the old A series, but with the newer modules you write FROM and TO statements in logic to copy data from the buffer memory in the module to the PLC's memory. Check for a FROM statement to be reading from that card and it should tell you the first address of the range.

Go to and go into Documents And Downloads, select Industrial Automation in the top box, then PLC in the next, then PLC-A. Look for the manuals you may need there. I know they are all there.


Okkie le Roux

In Mitsubishi Xn is a digital input. If X140 relates to the an analog card's slot specifically it is status bits of the card. X141 would for instance mean Card Healthy and X142 Card Error.

Analog inputs is normally read into D or R registers and then scaled to an appropriate value. Different types of analog cards have different resolutions. You need to search for the instruction where the card's memory is read into the PLC (FROM instruction)

Thus will more or less have the form:
FROM H2 K10 R160 K8
This means you read FROM the card to the PLC
H2 is the Head Address of the Slot
K10 is the buffer memory location
R160 is the device in the CPU where you want to store the results of the FROM instruction
K8 means you want to read 8 16 bit words and store them from R160 onwards.

Maybe you don't need this anymore.