Electro Cam 5000 Series - Manual (Page 40)

4-12 Programming, Standard Features
Setup Level Programming, Standard Controls: FCN 4
FCN 4 - Speed Compensation
(Setup or Master program enable must be active)
Speed Compensation is the ability of the control to
automatically advance an output's setpoints as the machine
speeds up, thus compensating for the response of the
device being controlled. Each output can be individually
compensated by a unique amount. This allows all output
devices to be properly compensated, even though their
responses may vary widely.
Standard speed compensation advances and retards both
the on and off edges of output pulses by the same amount,
proportional to the present machine speed.
Leading/Trailing Edge speed compensation, available on
controllers with the “L” option, allows a different amount of
compensation to be set for the leading and trailing output
edges in each channel. See page 5-1 for details.
Gray Code speed compensation is available on controllers
with the “G” option. See page 5-3 for details.
Speed compensation is set in units of Degrees/1000 RPM,
regardless of the scale factor being used. If the response of
the output device is known, the amount of Speed Comp
required can be calculated:
Speed Comp (Deg/1000 RPM) = 6 x response (in mSec)
EX: 20 mSec response: 6 x 20 = 120 (Deg/1000 RPM)
Program the output for the correct on and off setpoints at
zero speed and then program speed comp value.
If the device response is not known, program output for the
correct on and off setpoints at zero machine speed. Program
2nd
Press CHN key
to select output # 3rd
FCN 4 ENT
1st If FCN 4
not shown press:
Press number keys followed by
ENT to change Speed Comp
value
OR
DEC and INC keys can be
used to adjust Speed Comp
value in 1Deg/1000 RPM steps.
Present Speed Comp
value for selected
output channel shown Present Output
Channel
Selected
the output with an estimated speed comp value based on
six times the estimated response in mSec (mSec = .001
Sec). Run the machine at a typical speed and adjust Speed
Comp until the output is properly synchronized to the
machine.
Note: 1 Degree/1000 RPM resolution allows Speed Comp
to be adjusted very accurately. Because the adjustment is
so fine, it may be necessary to make larger changes to the
Speed Comp value to see a change in machine performance.
A change of 6 degrees/1000 RPM is needed to make a 1
mSec difference to the device being controlled.
FCN 4 - Negative Speed Compensation
(Input Gating)
(Setup or Master program enable must be active)
This feature is included on the following units which
were built after 5-19-92, date codes 9222 or greater. The
date code is printed beneath the model code on the
label on the back of the controller:
• All PS-51XX (Resolver) units
• All PS-50XX (Encoder) units date code 9740 or
newer, and units with "E" option prior to 9740.
Negative Speed Compensation causes an output channel
to lag its programmed machine position by the specified
degrees/1000 RPM. It is used when an input sensor is being
gated by the corresponding output channel into another
system (PLC, registration control, etc.) Since most sensors
have very fast response times, negative speed comp is
needed only where the sensor is slow to respond, or the
machine speeds are high and sensor timing is critical.
Example: Assume a product sensor requires 5 msec to
respond, and an output channel provides a reference window
to a PLC. The PLC will trigger an action only if the sensor
indicates a product is present during the output channel‘s
reference window. At 1000 RPM, the resolver will rotate (5
msec x 6), or 30 degrees during the sensor response time.
If the reference window isn’t also delayed by 30 degrees per
1000 RPM, the sensor signal may miss the reference
window.
Negative Speed Compensation is programmed in Deg/
1000 RPM. If the response of the input device is known, the
amount of Negative Speed Compensation needed can be
calculated:
Speed Comp (Deg/1000 RPM) = 6 x response (in mSec)
EX: 10 mSec response -6 x 10 = -60 (Deg/1000 RPM)
Because the PLuS control has individual speed
compensation for each output channel, it is possible to have
some outputs compensated positively while others are set
for Negative Speed Compensation.
(continued next page)
Note: Once programmed in a channel, this function will be present in that channel in all programs.