Rockwell Automation 1771-DB BASIC MODULE - Manual (Page 226)

Chapter
Call Routines 0–68 12
12 -36
Use CALL 38 to expand the type of errors the ONERR statement (page
11 -23) traps and handles.
The ONERR statement only allows the BASIC module to jump to an error
handling routine when it encounters an arithmetic error (number too large,
number too small, bad argument or division by zero occurs). All other
errors cause the module to enter Command mode. When you initiate
CALL 38, you allow ONERR to service other errors (except hardware
errors–watchdog, time-out, RAM failure, etc.) the BASIC module
encounters instead of returning to Command mode.
If any error occurs that causes a restart, stacks are cleared. Variables and
ports, however, are not re-initialized. This call has no effect until you
execute the ONERR statement within the program. This call is reset when
the BASIC module returns to the Command mode. You must re-execute
CALL 38 every time you enter Run mode.
Use CALL 0 (page 12 -2) if you want to reset the module within the error
routine.
Input and Output Arguments
This routine has one input and no output arguments. The input argument
determines if the expanded ONERR function is enabled or disabled:
0 = disable the expanded ONERR restart
1 (or any other number) = enable the expanded restart
If you perform an XBY in the error routine, this a list of the status codes
you might receive.
Status code Description
01 BASIC module attempted to call an illegal call number
02 port has been assigned an invalid parameter
03 string has not been dimensioned
04 defined string length is too small for operation
05 memory has not been allocated for this string
06 attempted to transfer to a RAM or ROM program that did not exist
07 command or call can only be executed from Command mode
08 user PROM has invalid checksum
09 this statement or call requires a user PROM; no user PROM is installed
10 divide by zero
11 DH-485 call executed and DH485 port not enabled
12 argument stack problem
13 syntax error
14 control stack problem
15 array size problem
16 internal processor stack problem
CALL 38: Expanded ONERR
Restart
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