Siemens SINUMERIK 840C Installation Instructions Manual page 202

09.95
155
Default value
4
The sampling interval is defined as the time after which the control outputs a new setpoint
speed to the axes. For axes or spindles, this NC MD can be additionally influenced, i.e. slowed
down by means of a multiplier (NC MD 1396* and 466*).
See Section Axis (Analog) and Spindle Installation.
Table with possible input values
System cycle Servo cycle
ms ms
(MD 168) (MD 155)
1 ms 8 ms
1 ms 4 ms
0.75 ms 3 ms
0.625 ms 2.5 ms
0.5 ms 2 ms
0.5 ms 1 ms
0.5 ms 2) 1 ms
3)
0.125 ms 0.125 ms
as from SW 4 as from SW 4
156
Default value
200
The enable signal for the speed controller (servo enable) on the measuring circuit is removed
when the programmed delay time has elapsed. There is a separate servo enable signal on the
measuring circuit for each axis; the control supplies these signals on a mode group basis.
The programmed delay time has the following effects:
1. Once the interpolator has reached the programmed position, the clamping tolerance
(MD 212*) is activated when the delay time has elapsed. The following error must therefore
be smaller than the clamping tolerance at this instant. The delay must be chosen so that it
is possible to reduce to zero the largest possible following error (rapid traverse). In the
event of an error, the servo enable signal is revoked on the measuring circuit and alarm
112* (zero-speed monitoring) activated.
This applies only when NC MD 372* (zero-speed monitoring delay) is 0.
_______
* Standard value
1) The lower limits only apply if the control is operated with one channel and 3 axes.
2)
486 CPU only.
3) 486 DX2 or DX4 only.
©
Siemens AG 1992 All Rights Reserved
SINUMERIK 840C (IA)
6 NC Machine Data (NC MD), NC Setting Data (NC SD)
Position control basic cycle time
Lower input limit Upper input limit
1)
1
IPO cycle MD 168
ms
(MD 160)
32 ms 16
16 ms 16 *
12 ms 12
10 ms 10
8 ms
4 ms
2) 3 ms 2)
3) 3)
1 ms
as from SW 4 as from SW 4
OFF delay for servo enable
Lower input limit Upper input limit
0
6FC5197- AA50
6.2 General machine data (general data)
Multiple of drive basic
40
cycle time
MD 155
8
4 *
4
4
8 4
8 2
8 2) 2 2)
3) 3)
2 1
as from SW 4 as from SW 4
1 000
Active on
Power On
Units
MD 160
4
4 *
4
4
4
4
3 2)
3)
8
Active on
Power On
Units
ms
6–17