Output File

contains 32 16-bit entries used by ladder program to command 

module operation. The Output File may also be used to supply 

process data to the module in certain situations. Entries in this 

file are updated automatically, at the end of each scan, by the 

SLC processor from the user data file but may be written at any 

time by immediate I/O instructions in the ladder program.

Input File

contains 32 16-bit entries used by ladder program to extract 

status information from the module. The Input File contains 

acknowledge bits corresponding to control bits in the Output 

File, as well as information pertaining to the profile executing on 

each analog I/O channel (step number, setpoint, analog input, 

process variable, control output, etc.) and a parameter error flag. 

The entries in this file are read automatically, once per scan, by 

the SLC processor into the user data file, but may be read at any 

time by immediate I/O instructions in ladder program.