Owner manual
3-4 MicroLogix™ 1200 IO 8 Ch Output Module
User’s Manual Pub. 0300246-01 Rev. B
3.4.1 Output Data File (Command Mode)
The output data file is used to configure each channel for the OF8 as well as control the
output signal of each channel. Use the addressing scheme below to locate the 8 output
words needed to configure the module.
Figure 3-2 (Output Addressing Scheme)
(1) I/O located on the controller (embedded I/O) is slot 0. I/O added to the controller (expansion I/O) begins
with slot 1.
The module enters a special mode called Command Mode when the PLC transitions from
Program mode to Run mode. When the module enters Command Mode, the output file is
used to send commands to the module and the module responds via the input data file.
The table below shows the layout for each output word during both modes of operation.
See Table 3-6 for command mode response data.
Table 3-1 (Normal Mode/Command Mode)
Output File
Output Word
Normal Run Mode Command Mode
O:e.0 Channel 0 Data Word Command
O:e.1 Channel 1 Data Word Data Word 1 (Ch0 & 1)
6
O:e.2 Channel 2 Data Word Data Word 2 (Ch2 & 3)
6
O:e.3 Channel 3 Data Word Data Word 3 (Ch4 & 5)
6
O:e.4 Channel 4 Data Word Data Word 4 (Ch6 & 7)
6
O:e.5 Channel 5 Data Word Fixed Word 1 (0xCDEF)
O:e.6 Channel 6 Data Word Fixed Word 2 (0xFEDC)
O:e.7 Channel 7 Data Word Fixed Word 3 (0x5A5A)
Once the module detects the transition from Program to Run it waits until the Fixed
Words and Command code are set to valid values. The first command must be Unlock.
If an error is detected, a non-zero response will be placed in the Response Code (see
Input Data File table).
Keep in mind the module is constantly polling the output file as it is updated by the
controller. The module will validate each command using the following three step
process:
1) Validate Fixed Words 1-3:
These words must always be valid during Command Mode. An error will be
posted in the Response Code until these are correct. Commands will not be
validated and processed until these words are set correctly. The fixed words are
posted above in Table 3-1.
6
See Table 3-3 (Data Words 1 through 4)