GE PACSystems RX7i - Page 163

Chapter 4. Ladder Diagram (LD) Programming
148 PACSystems* RX7i, RX3i and RSTi-EP CPU Programmer's Reference Manual GFK-2950C
Operands for BUS_RMW
For BUS_RMW_WORD, the absolute bus address must be a multiple of 2. For BUS_RMW_DWORD, it
must be a multiple of 4.
The absolute bus address is equal to the base address plus the offset value.
Parameter
Description
Allowed Operands
Optional
OP
Type of operation:
0 = AND
1 = OR
Constant
No
MSK
The data mask. DWORD constant or variable.
All except %S—%SC
No
R
Rack number. UINT constant or variable.
All except %S—%SC
No
S
Slot number. UINT constant or variable.
All except %S—%SC
No
SS
Subslot number (optional, defaults to 0). UINT
constant or variable.
All except %S—%SC
Yes
RGN
Region (defaults to 1). WORD constant or
variable.
All except %S—%SC
Yes
OFF
The offset in bytes. DWORD constant or
variable.
All except %S—%SC
No
ST
The status of the operation. WORD variable.
All except variables located in %S—
%SC, and constants
Yes
OV
Original value. DWORD variable.
All except variables located in %S—
%SC, and constants
Yes
BUS_RMW Status in the ST Output
The BUS_RMW function returns one of the following values to the ST output:
0
Operation successful.
1
Bus error
2
Module does not exist at rack/slot location.
3
Module at rack/slot location is an invalid type.
4
Start address outside the configured range.
5
End address outside the configured address range.
6
Absolute address even but interface configured as odd byte only
7
For WORD type, absolute bus address is not a multiple of 2. For DWORD type, absolute bus address is
not a multiple of 4.
8
Region not enabled
9
Function type too large for configured access type.
10
Function parameter invalid.