IAI America SCON-C - Manual (Page 157)

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 Push & hold operation
The following limitations apply in solenoid valve mode 2 [3-point type]:
 The position complete signal (PEND) is not available.
 In push & hold operation, the rear end position detected (LS0), front end position detected (LS1) and
intermediate position detected (LS2) signals turn ON only when the actuator has reached a point within
the positioning band (parameter No. 10) with respect to the target position. Accordingly, these signals
cannot be used to notify completion of push & hold operation.
This means that push & hold operation must follow a procedure different from the one used in other PIO
pattern operations.
Specifically, use the following procedure when performing push & hold operation in solenoid valve mode 2 [3-
point type]:
[Basics of push & hold operation]
[1] Enter the current-limiting value in the “Push” field corresponding to the front end (position No. 1) to
define that the front end command specifies push & hold operation.
[2] In the “Positioning band” field, enter the maximum distance (relative distance) to be traveled in push &
hold operation, calculated from the front end position.
(Consider the position error associated with the installation of the load, or the amount of decompression
if the load is made of elastic material.)
[3] If there is a possibility that the equipment may miss the load, use the zone output signal to determine
whether the load was missed. To do so, in the “Zone+” and “Zone-” fields enter values defining the zone
within which the push & hold operation is deemed to have completed successfully.
[4] Change the value in parameter No. 6 (Push completion judgment time), if necessary.
[5] Change the value in parameter No. 34 (Push speed), if necessary.
(These parameters have been set at the factory to values appropriate for the applicable actuator model.)
* For the parameter details, refer to Chapter 6, “Parameter Settings.”
(Example) An example is given where push & hold operation is performed using a rod-type actuator with a
200-mm stroke based on a current-limiting value of 40%, maximum travel distance in push &
hold operation of 20 mm, and successful push completion zone of 180 mm to 185 mm.
Enter 160 mm, 40%, 30 mm, 185 mm and 180 mm in the “Position” field, “Push” field,
“Positioning band” field, “Zone+” field and “Zone-“ field, respectively, in the position table under
No. 1.
Example of position table
No.
Position
[mm]
Push [%]
Positioning
band [mm]
Zone+
[mm]
Zone-
[mm]
Comment
0 5.00 0 0.10 100.00 4.90 Rear end (standby position)
1 160.00 40 30.00 185.00 180.00 Front end
2 * * * * * Intermediate point