GE PACSystems RX7i Cpu Programmer's Reference Manual page 165

Chapter 4. Ladder Diagram (LD) Programming
BUS Write
When the BUS_WRT function receives power flow through its enable
input, it writes the data located at reference (IN) to the module at the
specified rack (R), slot (S), subslot (SS) and optional address region
(RGN) and offset (OFF). BUSWRT writes the specified length (LEN) of
data units (DWORDS, WORDs or BYTEs).
The BUS_WRT function passes power to the right when its operation
is successful. The status of the operation is reported in the status
location (ST).
Note: For each BUS_WRT function type, use the corresponding data
type for the IN operand. For example, BUS_WRT_BYTE
requires IN to be a BYTE variable.
Note: An interrupt block can preempt the execution of a BUS_WRT
function. On the bus, only 256 bytes are written coherently
(i.e., written without being preempted by an interrupt).
Operands for Bus Write
Parameter Description
Length (??) Length. The number of BYTEs, DWORDs, or WORDs. 1 to
32,767.
IN Reference for data to be written to the module. DWORD
variable.
R Rack number. UINT constant or variable.
S Slot number. UINT constant or variable.
SS Subslot number (defaults to 0) UINT constant or variable.
RGN Region. (defaults to 1) WORD constant or variable.
OFF The offset in bytes. DWORD constant or variable.
ST The status of the operation. WORD variable.
150 PACSystems* RX7i, RX3i and RSTi-EP CPU Programmer's Reference Manual
Mnemonics:
BUS_WRT_DINT
BUS_WRT_DWORD
BUS_WRT_WORD
Allowed
Constant
All except variables
located in %S—%SC,
and constant
All except %S—%SC
All except %S—%SC
All except %S—%SC
All except %S—%SC
All except %S—%SC
All except variables
located in %S—%SC,
and constant
GFK-2950C
Optional
No
No
No
No
Yes
Yes
No
Yes