GE 90-30/20/Micro Section 2: Program Organization and User References/Data , Subroutine Blocks (Series 90-30 PLC only)

2-16 Series 90-30/20/Micro Programmable Controllers Reference Manual – September 1998 GFK-0467K

Section 2: Program Organization and User References/Data

The total logic size for the Series 90-30 programmable controller can be up to 6 KB in size for a

Model 311 or Model 313 CPU, up to 16 KB in size for a Model 331, up to 32 KB in size for

Model 340 CPUs, 74 KB for Model 350 (32 KB for program logic) and, prior to Release 9, up to

80 KB for Models 341, 351 and 352 CPUs. Beginning with Release 9 CPUs, some memory sizes

for the 351, 352 and 360 series are configurable. (For detailed instructions and a discussion of

memory sizes available, refer to the “Configurable Memory on 351 and higher CPUs” in Chapter

10, Section 3 of the Logicmaster 90™ Series 90™-30/20/Micro Programming Software User’s

Manual (GFK-0466K or later). A program for the Series 90-20 programmable controller can be

up to 2 KB in size for a Model 211 CPU. A program for the Series 90 Micro programmable

controller can be up to 6 KB in size, up to 12 KB for a 28-point Micro.

The user program contains logic that is used when it is started up. The maximum number of rungs

allowed per logic block (main or subroutine) is 3000; for 90-30 PLCs, the maximum block size is

80 kilobytes for C bl ocks and 16 kilobytes for LD a nd SFC blocks, but in an SFC block some of

the 16 KB is used for the internal data block. The logic is executed repeatedly by the PLC.

read

a45660

PROGRAM

inputs

write outputs

Refer to the Series 90-30 Programmable Controller User’s Manual, GFK-0356, or the Series 90-

20 Programmable Controller User’s Manual, GFK-0551, for a listing of program sizes and

reference limits for each model CPU.

All programs have a variable table that lists the variable and reference descriptions that have been

assigned in the user program.

The block declaration editor lists subroutine blocks declared in the main program.

Subroutine Blocks (Series 90-30 PLC only)

A program can “call” subroutine blocks as it executes. A subroutine must be declared through the

block declaration editor before a CALL instruction can be used for that subroutine. A maximum of

64 subroutine block declarations in the program and 64 CALL instructions are allowed for each

logic block in the program. The maximum size of a subroutine block is 16 KB or 3000 rungs, but

the main program and all subroutines must fit within the logic size constraints for that CPU

model.