Siemens sinumerik 840D sl Function Manual page 577

Detailed description
2.5 Actual value
2.5 Actual value
Actual value in hardware
The actual position value of the analog axis is acquired by a signal generator. An unassigned
measured-value input for the direct measuring system on an active digital drive (SIMODRIVE
611D) is used as the measured-value input. This is the lower 15-pin measured-value input
with designation X422 on the digital drive.
As an example, a machine has 3 digital and one analog axis. The actual value of the analog
axis can be taken to a direct measured-value input of one of the 3 digital drives. The
selected digital drive must have a submodule for a direct measuring system. In other words,
an active digital drive is required for every analog axis.
Configure actual value
As far as the actual value is concerned, the analog axis must be configured so that its actual
value is applied to an unassigned measured-value input for the direct measuring system on
an active digital drive. Since the analog axis has only one position measuring system, only
one measuring system is activated in the machine data. Machine data 30200 to 30240 are
used for this purpose.
MD30200 $MA_NUM_ENCS = 1: Analog axis has one measuring system
MD30210 $MA_ENC_SEGMENT_NR = 1: Bus segment 840D
MD30220 $MA_ENC_MODULE_NR =: Module number of active digital drive
MD30230 $MA_ENC_INPUT_NR[0] = 2: Direct measuring system
MD30240 $MA_ENC_TYPE[0] = 1: Encoder type signal generator
The first measuring system is activated by the PLC-to-axis signal DB31-48, DBX1.5. It is not
possible to switch over to measuring system 2 and any attempt to do so is ignored.
12
Special functions: Analog Axis (TE2)
Function Manual, 11/2006, 6FC5397-2BP10-2BA0