GE VersaMax, Manual

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13-18 VersaMax® Modules, Power Supplies, and Carriers User's Manual – March 2003 GFK-1504K
13
IC200MDD841
Mixed Module, 24VDC Positive Logic Input 20 Points / Output 12 Point /
(4) High Speed Counter, PWM, or Pulse Train Configurable Points
Ramp Outputs
When an output’s function is selected to be Ramp (in the module configuration),
acceleration and deceleration factors are applied to the Pulse-Train output.
Acceleration and deceleration factors can be specified using Data Commands, as explained
later in this section. Both acceleration and deceleration can be selected from the range of
10 p/s
2
to 1,000,000 p/s
2
. The default for both is 1,000,000. Acceleration and deceleration
do not need to be the same. Appropriate values depend on the application and the
capability of the stepper motor being driven by the module.
A Ramp function begins when the module detects that the channel’s Enable Output bit
(discrete output bit 21-24, see “Module Data”) is On and an Off-to-On transition has
occurred on the channel’s Start Pulse Train bit (discrete output bit 25-28). At that point,
the Pulse Train begins and the channel’s Pulse Train Complete bit (discrete input bit 33-
36) is set Off. The module outputs the specified number of pulses, in varying pulse
widths, to produce a velocity profile similar to the one shown below. After the last pulse is
completed, the module sets the channel’s Pulse Train Complete bit Off and begins
monitoring the channel’s Start Pulse Train bit for another Off-to-On transition.
The Ramp feature results in a Pulse-Train profile similar to the example shown below.
Frequency = 5,000
Acceleration = 10,000
Deceleration = 2,000
2.5 0.5
Time
(seconds)
Velocity
(pulses/sec)
5,000
Once a Ramp function has started, it continues until all of its pulses have been generated or
its Output Enable bit (discrete output bit 21-24) changes from On to Off.
A Pulse Train output can be terminated before the requested number of pulses have been
completed by setting its Output Enable bit (discrete output bit 21-24) to Off. If the Enable
Output bit transitions from On to Off, the module will either stop the Pulse Train
immediately or transition the Ramp output to its deceleration phase—depending on the
channel’s configuration. If deceleration is configured, the module will output a number of
pulses based on: (1) the configured deceleration and (2) the velocity at the time the Enable
Output bit goes Off. When the last pulse is completed, the module will set the channel’s
Pulse Train Complete bit (discrete input bit 33-36) to On.
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