User Manual

XL7 User Manual
11.5.3 HSC Output (High Speed Counter Match)
When either Q1 or Q2 is configured for HSC Output operation, HSC1 or HSC2 turns on, off or toggles
based on a comparison between the counter accumulator and match registers. See details above in the
high speed input section.
11.5.4 Stepper Function
The XL7 supports two stepper functions, one on each high speed output.
The Stepper requires five parameters (%AQs) to be set for operation. These parameters may be set at
run-time but are ‘latched’ when the stepper is commanded to start:
Start Frequency
(cycles per second)
This value sets the frequency for the first cycle during the acceleration phase and
the frequency of the last cycle during the deceleration phase. When an
acceleration or deceleration count is specified, the Start Frequency must be
greater than 0 and must not exceed the run frequency or an error is generated.
Run Frequency
(cycles per second)
This value sets the frequency for the last cycle during the acceleration phase, the
consistent frequency during the run phase, and the frequency of the first cycle
during the deceleration mode. The Run Frequency must be greater than 0 and
must not exceed 5000 cycles/sec. or an error is generated.
Acceleration Count
This value sets the number of cycles to occur within the acceleration phase. The
frequency of the cycles within this mode will vary linearly between the specified
Start and Run frequency. The Accel count must not equal 1 or an error is
generated. Setting this value to zero disables this phase.
Run Count
This value sets the number of cycles to occur within the run phase. The
frequency of the cycles within this mode is constant at the specified Run
frequency. The Run count may be any value. Setting this value to zero disables
this phase.
Deceleration Count
This value sets the number of cycles to occur within the deceleration phase. The
frequency of the cycles within this phase will vary linearly between the specified
Run and Stop frequency. The Decel count must not equal 1 or an
error is
generated. Setting this value to zero disables this phase.
The stepper provides two Boolean registers to provide stepper status:
Ready/Done
A high indication on this register indicates the stepper sequence can be started
(i.e. not currently busy).
Error
A high indication on this register indicates that one of the analog parameters
specified above is invalid or the stepper action was aborted before the operation
was complete. This register is cleared on the next start command if the error
was corrected.
The stepper requires one discrete register to control the stepper action. Setting this register starts the
stepper cycle. This register must remain set to complete the entire cycle. Clearing this register before
the cycle is complete aborts the step sequence and sets the error bit.
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