stepmove drifting?

[dan]

Hi,

I have two problems.

1. I'm working on a program that looks like will be more than 6016. I know about M2018P. My question is if I need more than 8290 there is a solution available ?

2. Using step and direction I'm driving a servo. To keep track of positions and for comunications I use variables and DMs
If I issue a StepMove 1,R,50 and R ends up to be zero (R=DM[]-actual position) the PLC is issuing steps with a very slow speed.
I tested this on a very simple program (one circuit only) with the same result.

Please let me know

Dan

[support]

The 8190 steps is the maximum program steps that the M-series PLC can have. There is no other expansion options. There are many ways to streamline a program. Your program may contain a lot of strings that are repeated and these can be stored in String variables and applied at different area instead of repeating them as spring constant. One possible option is to store strings as data in the EEPROM using SAVE_EEP$ command. You can first transfer a program to store these string data into the EEPROM, and the actual program that uses these string are then loaded into the PLC to use the data strings that are already stored into the EEPROM. (Transfering of a new program to the PLC does not affect the data EEPROM).

Stepmove of zero step does not make sense to the program. In fact, the minimum number of steps allowed is 2. Unfortunately the firmware did not specifically test for step = 0 condition and it ends up being put into an unexpected move. So you may want to conduct a test to ensure that your step is not less than two. E.g.

   IF ABS(R) < 2  RETURN: ENDIF