743
Table Data Processing Instructions Section 3-17
Operand Specifications
Description SNUM(638) counts the number of data words in the specified stack from the
beginning of the data region at TB+4 to the address before the one indicated
by the stack pointer (TB+3 and TB+2). SNUM(638) does not change the data
in the stack or the stack pointer.
Flags
Area TB D
CIO Area CIO 0000 to CIO 6143
Work Area W000 to W511
Holding Bit Area H000 to H511
Auxiliary Bit Area A448 to A959
Timer Area T0000 to T4095
Counter Area C0000 to C4095
DM Area D00000 to D32767
EM Area without bank E00000 to E32767
EM Area with bank En_00000 to En_32767
(n = 0 to C)
Indirect DM/EM
addresses in binary
@ D00000 to @ D32767
@ E00000 to @ E32767
@ En_00000 to @ En_32767
(n = 0 to C)
Indirect DM/EM
addresses in BCD
*D00000 to *D32767
*E00000 to *E32767
*En_00000 to *En_32767
(n = 0 to C)
Constants ---
Data Registers --- DR0 to DR15
Index Registers ---
Indirect addressing
using Index Registers
,IR0 to ,IR15
–2048 to +2047 ,IR0 to –2048 to +2047 ,IR15
DR0 to DR15, IR0 to IR15
,IR0+(++) to ,IR15+(++)
,–(– –)IR0 to, –(– –)IR15
A
TB
TB+1
TB+2
TB+3
TB+4
N
m
n
D
n
m
Counts the number of words
(N) from the address of the
beginning of the stack (TB+4)
to the pointer position −1.
PLC memory
address
Pointer
Last word
in stack
Stack
Name Label Operation
Error Flag ER ON if the number of words of data in the stack (the value
output to D) is 0.
OFF in all other cases.