Publication 1762-RM001C-EN-P
Input and Output Instructions 17-3
IOM - Immediate Output
with Mask
Instruction Type: output
The IOM instruction allows you to selectively update output data without
waiting for the automatic output scan. This instruction uses the following
operands:
•
Slot - The slot is the physical location that is updated with data from
the output file.
•
Mask - The mask is a hex constant or register address containing the
mask value to be applied. If a given bit position in the mask is a “1”,
the corresponding bit data is passed to the physical outputs. A “0”
prohibits corresponding bit data from being passed to the outputs.
The mask value can range from 0 to 0xFFFF.
•
Length - This is the number of masked words to transfer to the
outputs.
IOM
Immediate Output w/Mask
Slot O:0.0
Mask N7:0
Length 1
IOM
NOTE
This instruction is used for embedded I/O only. It is not
designed to be used with expansion I/O.
Table 17.3 Execution Time for the IOM Instruction
Controller When Rung Is:
True False
MicroLogix 1200 22.3
µ
s0.0
µ
s
MicroLogix 1500 1764-LSP 18.4
µ
s0.0
µ
s
MicroLogix 1500 1764-LRP 19.4
µ
s0.0
µ
s
IMPORTANT
Slot 0 is the only valid slot number that can be used
with this instruction. IOM cannot be used with
expansion I/O.
Bit 1514131211109876543210
Output Data Output Word
Mask 0000000011111111
Real Outputs Data is Not Updated Updated to Match Output Word