$ALM_IF variables and reading errors

Hi, I need to send alarms from robot to plc via modbus. I can't buy more options.
I got to read $ALM_IF.$LAST_ERCODE and I get unique codes for each alarm in my register. Is there a table to know which error it is? I would like to map some expected errors to simple variables and send anything else as "other error" so our monitoring from PLC can know what's happening.

If there's a better option to use over modbus I'd love to hear that too. I don't have karel or error code output (or probably any other paid option)

I found in appendix A of Handling tool manual the explanation how error codes should be assembled, but I can't read it from $ALM_IF

Alarms I could get easily and the codes in $LAST_ERCODE

SRVO_001 - 906690561
SRVO_002 - 906690562
SRVO_003 - 906690563

INTP_254 - 101449982

Is there a list with this encoding of the alarms? So if I know some alarm code I can know the number without reading it there?

I got another problem, I can't compare this with IF because when I try to enter this code manualy to register or as constant it changes it, probably because of some rounding. All 3 SRVO alarms become 906690560, and INTP_254 changes to 101449982.

If I leave it like that IF function returns false. I tried to calculate mod 1000 and compare with just last 3 numbers and that works, but I don't know all codes, I don't know if I'll get false alarms with using just last few digits

So while this "hack" will work and output a last alarm, with probably significnt enough number of digits, I don't know the mapping of it to any real alarms and I'll have to write it manually every time new alarm occurs, so if anyone has a better solution please save me from this