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Chapter 3
Control Program Integration
Similar to how you customized your Axis User Programs above, change the operation of the Machine
Control to reflect your application needs. If simultaneous control is needed, consider using Broadcast
commands. If individual or step-by-step control is needed, consider using Axis commands and controlling
each axis individually.
Be sure to initialize or set the Axis command parameters before you execute each Axis command. This will
TIP
help make sure that each command is always executed using the expected parameters.
Alter the Ultra1500 Drive Follower Gear Ratio
As explained in
Chapter
Follower Counts relationship. In your case, this means the number of PTO Counts to Encoder Counts. The
MicroLogix1400 application code is based on a 1:109 gear ratio and must be set accordingly, otherwise the
Ultra1500 drive may misinterpret the PTO counts outputted from the MicroLogix 1400, resulting in
unexpected motion.
Not all PTO count to motor encoder count relationships can be represented in Ultraware due to the
limitation of the Gear Ratio parameter and thus some very small error can be expected with each PTO based
move. If your application requires a higher degree of precision, a different Ultra1500 drive Follower Gear
Ratio can be chosen, but there are application tradeoffs that are explained below.
As explained in the ladder logic comments in the AX#_CALC routine, the Ultra1500 drive Follower Gear
Ratio is defined by the Encoder Resolution [counts/rev], the Maximum Application Speed [RPM] and the
Maximum PTO Frequency [Hz].
Gear Ratio =
Max PTO Freq [Hz]
Application Resolution [encoder_counts/sec]
Application Resolution [encoder_counts/sec] =
Encoder Resolution [encoder_counts/rev] * Max Application Speed [RPM]
The AX#_CALC routine calculates a normalized gear ratio in the format of 1/XXX. This is done to
accommodate the integer/integer format that the Ultra1500 drive Follower Gear Ratio requires. The XXX
value is determined by using the above equations in ladder logic (109 in the default case), but note that it is
rounded for most Encoder Resolution, Maximum Application Speed, and Maximum PTO Frequency
combinations. This produces a very small rounding error that is introduced into the system when translating
44
1, the Ultra1500 drive Follower Gear Ratio parameter specifies the Master Counts to
60 [sec/min]
Publication CC-QS008B-EN-P - December 2009
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