STL program problem

Mikluk

I have created an logic to write values into the DB with 400 bytes for each device divided to 2 parts / faults and alarms. That means the first byte for the first device is on the address 200. Next is on the 600 and so on 11^thstarts on the address 4200. I am calculating address in the STL but the problem is that when I want to write data for 11^thblock ( that means on the address 4200 ) PLC is giving error “Area length error when writing”. The last byte on which I can access is at address 4199.

Hi Mikluk

As your logic is based on +AR1 pointer calculations, I'll hazard a guess and say this is the root cause of your issue.

Put simple, and with reference to Step 7 inbuilt help, the following applies:

+AR1: The integer (16 bit) to be added to the contents of AR1 is specified by the value in ACCU 1-L. Values from -32768 to +32767 are permissible.

This means the maximum address you can add to AR1 via +AR1 command is 4095.7 which is not quite enough for what you want to do.

Solution is to get rid of the +AR1 commands and use good old +D instead to calculate the address followed LAR1.

Have a look too at THIS THREAD for more info.