Beck, R&J ELECTRIC ACTUATORS FOR INDUSTRIAL PROCESSCONTROL 11-1_9 用户手册

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In order to correctly position the drive output 

shaft in response to the Demand input signal, the 
DCM-2 receives a position signal from the drive’s 
position sensor and compares this actual position 
to the Demand input.  This process requires that the 
DCM-2 interprets the position signal appropriately 
for the full range of desired travel.  This procedure 
will calibrate the DCM-2 to accept the position signal 
and interpret the appropriate 0–100% range.  Note 
that all drives come factory calibrated and there is 
no need to recalibrate unless changes in operation 
are desired. 
 

It is also possible to calibrate the position signal 

using the HART or Serial interface.

 

Typically, it is best to use the full 100° (or 90°  

for quarter-turn valve drives) rotation of the drive 
in response to the 0–100% Demand input signal—
this allows full flexibility in arranging the drive’s 
torque to be distributed for the best mechanical 
advantage relative to the driven load.  
 

In certain applications, as a last resort, it may 

become necessary to reduce the full rotation of 
the drive.  In these applications, the DCM-2 can be 
calibrated to accommodate reduced stroke.  The 
recommended minimum full stroke rotation is 60° 
(although it is advisable to make the range as close 
to 100° (or 90°) as possible for the highest position 
resolution attainable with the CPS and to avoid 
reduction in torque (linkage connected drives); if 
the driven element stroke rotation is less than 100° 
(where applicable), a linkage can be used to allow 
the driven element to move the correct rotation 
while still allowing the drive to rotate 100°).
 

To reduce the full rotation of the drive (short-

stroke), use the customer interface panel and 
follow the "position calibration" instructions (this 
page).  Short-stroking can also be accomplished 
by using the HART (see page 55) or Serial (see 
page 71) interface.
 

The illustration below represents a Beck drive 

with linkage requiring an 80° full stroke rotation.  
(Please note that the crank arm may be adjusted 
to any start angle orientation).     

DCM-2 LOCAL INTERFACE

 

 

  1.  Remove the DCM-2 cover (1/2” bolt heads).
 2. Position the drive at the desired minimum 

position (i.e., the desired physical position of 
the drive’s output shaft corresponding to the 
0%  Demand input signal).

 3. Ensure the Handswitch is in the “STOP” 

position.  This will prevent the drive from 
repositioning during this procedure.

  4.  Press and hold the “CALIBRATE” pushbutton 

on the DCM-2 customer interface panel, then 
press the “SET POS 0%” pushbutton until the 
“ACKNOWLEDGE” LED is lit.*

 5. Position the drive at the desired maximum 

position (i.e., the desired physical position of 
the drive’s output shaft corresponding to the 
100%  Demand input signal).

 6. Ensure the Handswitch is in the “STOP” 

position.  This will prevent the drive from 
repositioning during this procedure.

  7.  Press and hold the “CALIBRATE” pushbutton 

on the DCM-2 customer interface panel, then 
press the “SET POS 100%” pushbutton until 
the “ACKNOWLEDGE” LED is lit.*

  8.  Optional:  Adjust the over-travel limit switches (see 

page 26) just outside the 0% and 100% limits.

  9.  Verify that the drive’s 0% and 100% positions 

are correct.  If not, repeat this procedure.

 10. Replace the compartment cover and tighten 

the cover bolts to 10 lb-ft (14 N•m) torque.

Crank arm may be adjusted to any start angle orientation.  
The orientation shown above has been randomly 
selected for the purpose of this example.

NOTE:

* If the “ACKNOWLEDGE” LED does not light, but 

the “POSITION” LED does light, the signal is out 
of acceptable range and was not accepted by the 
DCM-2.