Analog Signal In Unity Pro

Ok, some beginner questions here.

I have Unity Pro, the customer wants a 4-20mA signal to go into a IODDT? for monitor, and then the exact signal coming in going to a redlion meter on the front of the panel for the operator,

I have basic PLC experience almost entirely in RSlogix, I have got most of his program done but I cannot figure out how to get the signal into the PLC, and then write it out

as far as I can tell, I can use READ_TOPO_ADDR to drop it into a IODDT for the future programmer to use, but I cannot figure out how to write the value down to the output on the card

PLC Type - M340
Card - AMM0600

No, I have not brought an analog signal into a PLC in a very long time, and am scratching my head

Thanks for any help

Side Note : I am using LD as well to program it

anyone?

It has been a few years, and I only used Modicon once, sooo

The basic idea here is to use some instruction to move or write an integer value to the analog out register.

Look in your hardware config to find the analog out card and then either assign it a register or discover what the register is.

As I recall the hardware config is quite different from AB and is also a pain to navigate as a new user.

You should have a list of instructions in your documentation or help files.

I only posted as I saw no response and I thought this might point you in the right direction.

Here's what I ended up doing -

Set the card configuration to 4-20mA signal

and I used the Operate function with the st format

%QW0.6.4 := %IW0.6.0

QW being the analog out Designation
and IW being the analog in Designation

and the 4-20mA signal generated in, is shown on the our perfectly

Mosca said:

Here's what I ended up doing -

Set the card configuration to 4-20mA signal

and I used the Operate function with the st format

%QW0.6.4 := %IW0.6.0

QW being the analog out Designation
and IW being the analog in Designation

and the 4-20mA signal generated in, is shown on the our perfectly

Click to expand...

Glad you got it working.

Hardware config can be tricky, I always start there after making an I/O list.

It looks like what you have done is make an analog out unconditionally equal to an analog input.

That is not normally the case, but in your case, the "memory register" was not needed as you were writing an input directly to an output.

In most cases, one would use the analog in as the source of a scale function, then use that scaled number in the software to make decisions, and then based on a decision or condition write some value out to the analog output. Often the output is also scaled.

In this way it is possible to read 0-32,768 as 0-2000 units and the compare to some operation or condition , for example: A > Xunits.

Then if this is true write "some integer 0-2000" out to an output that might be scaled as 0-32768 = 3-15 PSI.

(Just in case you want to go back and add some condition to your code.)

Ah yes, I did add it to the data table in order to read it, but I have not control over what the extended customer is planning on doing with it.

I made the variable T_ANA_IN_BMX and T_ANA_OUT_BMX

From what I was told, bring the signal in and then right out to a pair of red lion displays, the extended customer will address the analog signals in their PLC system to monitor the system

So far its worked, I do hope they have people who can edit this as necessary