GE 90-30 Forcing Bits

[turbohamad]

Dear Fellows;
I am working on a very old machine which is designed in GE 90-30 PLC system.
I have some difficulties like

1. How a force to discrete input and output device like switches or solonied etc? can i also force the %M?

2. How i know that programmer use the maximum %R or %M address because i need some modification and use the %R and %M which is not using before?

3. How i over ride the %AI and % AQ to check the values before start, Suppose %AQ is 0-32000 counts for 0-50 mA. I want to check by applying 10000 to %AQ to check the behavior before start.

Regards

 

[Steve Bailey]

How a force to discrete input and output device like switches or solonied etc?

Forcing is a two-step process. The first step is to force the point. The second step is to toggle between the on or off states. The details of how to do it depend on the software you're using to monitor the action.

can i also force the %M?

Yes

How i know that programmer use the maximum %R or %M address because i need some modification and use the %R and %M which is not using before?

When you enter a new instruction, type the address designator only, without the numeric part (%M instead of %M0123). The software will select the next available address in that data type. Works for Logicmaster, VersaPro and PME.
You can't force analog inputs or outputs.

 

[turbohamad]

Thanks steve;
I am using LM 90 software, how i force the %I or %Q or %M?

In LM 90 it means i am not able to write counts to %R where %AQ or %AI data move?

For example a transmitter 4-20 mA = 0-32000 counts and this data move to %R0001 if i want to check by passing 16000 to %R0001 after the move instruction is it possible?

Regards

 

[Steve Bailey]

I am using LM 90 software, how i force the %I or %Q or %M?

You must be online and in "Logic Equal" state. Move the cursor to the bit you want to force. F11 will turn on forcing for that address. F12 will toggle between states. Remember that once forced, a bit is no longer under control of the program, so be sure to cancel the force by hitting F11 again once you no longer need to force the bit.

In LM 90 it means i am not able to write counts to %R where %AQ or %AI data move?

You can write to any of those addresses, but if the ladder logic also writes to them it will take precedence over what you try to write. The techniques for forcing that I described ablove do not apply to %R. %AI, or %AQ.

For example a transmitter 4-20 mA = 0-32000 counts and this data move to %R0001 if i want to check by passing 16000 to %R0001 after the move instruction is it possible?

You can enter a new rung of logic to do that, but if you position the cursor over the address and write a different value to it that value will only be active for a single program scan.