GE 90-30/20/Micro Enhanced DO I/O Function for 331 and Later CPUs

GFK-0467K Chapter 4 Series 90-30/20/Micro Instructions Set 4-113
4
Enhanced DO I/O Function for 331 and Later CPUs
Caution
If the Enhanced DO I/O function is used in a program, the program should
not be loaded by a version of Logicmaster 90-30/20 software prior to 4.01.
An enhanced version of the DO I/O (DOIO) function is available for Release 4.20, or later, of
Models 331 and later CPUs. This enhanced version of the DOIO function can only be used on a
single discrete input or discrete output 8-point, 16-point, or 32-point module.
The ALT parameter identifies the slot in the main rack that the module is located in. For example,
a constant value of 2 in this parameter indicates to the CPU that it is to execute the enhanced
version of the DOIO function block for the module in slot 2.
Note
The only checking done by the enhanced DOIO function block is to check the
state of the module in the slot specified to see if the module is okay.
The enhanced DOIO function only applies to modules located in the main rack. Therefore, the
ALT parameter must be between 2 and 5 for a 5-slot rack or 2 and 10 for a 10-slot rack.
The start and end references must be either %I or %Q. These references specify the first and last
reference the module is configured for. For example, if a 16-point input module is configured at
%I0001 through %I0016 in slot 10 of a 10-slot main rack, the ST parameter must be %I0001, the
END parameter must be %I0016, and the ALT parameter must be 10, as shown below:
|
| _____
|%I0001 | | %Q0001
|——| |———|DO_IO|———————————————————————————————————————————————————————————( )-
| | |
| | |
|%I0001 -|ST |
| | |
| | |
|%I0016 -|END |
| | |
| | |
| IO —|ALT |
| |_____|
|
The following table compares the execution times of a normal DOIO function block for an 8-point,
16-point, or 32-point discrete input/output module with those of an enhanced DOIO function block.
Module Normal DOIO Execution Time Enhanced DOIO Execution Time
8-Pt Discrete Input Module
8-Pt Discrete Output Module 224 microseconds 208 microseconds 67 microseconds 48 microseconds
16-Pt Discrete Input Module
16-Pt Discrete Output Module 224 microseconds 211 microseconds 68 microseconds 47 microseconds
32-Pt Discrete Input Module
32-Pt Discrete Output Module 247 microseconds 226 microseconds 91 microseconds 50 microseconds