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TB142 Rev1 Modifying PLCIO2 based PLC Programs
for v8 00+ Rapid Override Function Key
Overview
Starting with software version v8 00 a new feature has been added that places an F7 function key in CNC7
software when in MDI mode or otherwise running a job It is intended that the F7 key can be used to toggle the
rapid override state and also work in conjunction with a jog panel PLC program combination if this
combination is already present For existing PLCIO2 based systems the F7 key will not work as control of the
rapid override state because the PC side PLC program controls it This situation can be remedied by
modifying the CPU7 side PLC program to control the rapid override state
Modifying the CPU7 side PLC program
The CPU7 side PLC program is found in the C \PLC directory and has an extension of SRC Note that in
PLCIO2 based systems there are at least two SRC files To identify which one is the CPU7 side PLC
program look for the SRC file to have a filename that includes the string "CPU" such as ATC10CPU SRC
V3ECCPU SRC or HCNCCPU SRC Other ways to determine the CPU7 side PLC program are to look at the
header comments in C \CNC7\CNC7 PLC or to edit the source code file and look at the program syntax
CPU7 program lines have the form PLC_BIT = whereas the PC side PLC programs have the form IF
THEN
Once the correct CPU7 side PLC program is located edit the file and make the following changes
In the memory definition section of the source code add the following line
Last_rapid_over_key IS MEM73
In the program section remove the line
Rapid_override = PC_Rapid_override
and replace it with these lines
Rapid_override = Rapid_override XOR Rapid_over_key AND
/ Last_rapid_over_key
Last_rapid_over_key = Rapid_over_key _
Save the file with a new name in case there are problems For example it will be assumed that the original file
was ATC10CPU SRC and the new file was named ATC10CP2 SRC Recompile the PLC program
C \PLC>plccomp atc10cp2 src
There should be output to the screen that compilation was successful Now copy the PLC program to the
C \CNC7 directory Note that for lathe systems the PLC file is copied to C \CNC7T
C \PLC>copy atc10cp2 plc \cnc7\cnc7 plc
At this point the CNC7 software can be restarted or the system can be rebooted The rapid override F7 key
should now toggle the rapid override state and so should the jog panel rapid override key
Document History
Rev1 Created on 2002 04 26