PID in Q Series

[justwhy2003 0]

Greetings I am looking for a bit of advice on using PID in a Q25UDHCPU. I am using GX Works 2. I am modifying a program that has 8 PID loops configured in complete derrivative mode. I cannot change the original program but can add additional code to it. I need to add 6 PID loops to the program. This would be fairly easy to do except that as the PIDINIT and PIDCONT commands need about 142 and 261 consecutive words for the configuration of 14 loops. I cannot extend the current configuration words due to other addresses in the program. As an alternative, I can see in the manual that complete and incomplete derrivative should be able to run at the same time "Since the incomplete derivative PID control instructions and complete derivative PID control instructions are independent of each other, they can be executed at the same time." I was hoping to set up 6 incomplete derrivative loops using a different range and the S.PIDINT and S.PIDCONT commands. I have tried this today but didnt have it working as I left, will return to it next week. Has anyone done this or had any experience in using both at the same time? Should this work? Thanks JT

[justwhy2003 0]

Update to the above. This works as an option. I set up a separate 6 PID loops using the S.PIDINIT and S.PIDCONT commands as well as the original 8 loops using PIDINIT and PIDCONT and can operate all PID loops at the same time. I hear another option may have been to download PID blocks from the Mitsubishi library but I have only heard about this last week and I got the S.PID option working a few weeks ago. If anyone has used the blocks option I would be interested to hear if they are comparable to the standard blocks and if there are any advantages/disadvantages to this as an alternative. Thanks JT