Configuration Data For The Path C To A - Siemens SIMATIC S5 Manual

IP 267
6.6.3

Configuration Data for the Path C to A

The configuration data is stored as 4-byte message frames in output bytes QB 88
to QB 91 of the PIQ. You should define the limit switch configuration first. The
power section has been set to full-step mode, e.g by jumpers. You must set the
"STOP" mode so that the configuration data is accepted by the IP 267. This data
must be written into QB 89 of the PIQ as byte 1 ( Table 6-2.).
The following applies for this example: QB 89 = 00000010 = 02
The base value (BV) for the stepping rate and the start/stop rate must then be
calculated. Select as small a base value for both frequencies as possible so that
you can set a discrete stepping rate and start/stop rate. However, the base value
must be large enough to achieve the desired maximum stepping rate. Calculate
the base value according to the following formula in order to achieve the
stepping rate (f ) of 10 kHz:
A
10 000 Hz
V is the multiplier for the velocity and for R you can select the reduction factor 1
or 0.1.
The value calculated for BV is coded with bits FB 0 and FB 2 and written into QB
91 of the PIQ as byte 3 of the configuration message frame ( Table 6-2.).
The following applies for this example: QB91 = 00000100 = 04
You must take account of the "Moment of inertia as a function of the permissible
start/stop rate" curve in order to be able to configure the correct start/stop rate
( Figure 6-6.). For this purpose, you must take account of the moment of inertia
of all moving parts in your drive (linear and rotary including the stepper motor
rotor). The configured value for the start/stop rate must be in the lower part of
the curve.
EWA 4NEB 812 6061-02a
f = BV G *
*
A
= BV * 250 *
BV = 40 Hz
Application Examples
H
R
1
H
6
6-27