Adding analog input card to Modicon M580 BMEAHI0812 is one of the most important knowledge to have as without analog input modules there is no IO actions.

I will start off with how to add the analog input card using a DTM Browser. The I will go into detail explanation on how to set the BME AHI 0812 analog input card identifier though the Address Setting tag which is essential to making the BME AHI 0812 analog input card work. If an improper Identifier is assigned, the BME AHI 0812 analog input card will not work. This tutorial, I will also show you how to disable HART (all 8 channels) as we will be using exclusively 4 to 20mA signals. If you don’t disable HART and try to use 4 to 20mA, you will not be able to read the 4 to 20mA signal going into the BME AHI 0812 analog input card channels (as they are default configured for HART communication). Finally I will underscore DHCP issue with IP address assignment and how to debug it.

Below are main reason to why you should use BMX AMI 0810 analog input card if you are only using 4 to 20mA and there if no plans for HART transmitters.

1) Configuration is tedious. The configuration is tedious and conviluted. If you miss a step the BME AHI 0812 analog input card will not communicate.
2) Cost. The cost of BMEAHI0812 is definately higher than BMX AMI 0810 analog input card. Naturaly as it has the ability to support HART
3) Network Setting & Cybersecurity. If the Modicon M580 PLC is conected to a network with DHCP server in it, the DHCP server in the Modicon M580 will conflict with the DHCP server in the network. The simple way to tell if there is a conflict is that the CRA will take anywhere from 5minutes to 2 hours for it to come online (RUN LED turning green).

Resolving DHCP Issue
If in the event if 2 DHCP server have to exist in the controls network, you will gave to put some sort of a firewall rule to block traffic (incoming and outgoing) from port 67 and 68 ( standard DHCP TCP port number). Alternatively, you can put the two DHCP servers on two separate VLAN.

Below is the link to where you can get a user manual on how to setup an Identifier for the analog input card. See page 148 of the “Modicon eX80 BMEAHI0812 HART Analog Input Module & BMEAHO0412 HART Analog Output Module User Guide”