Specifications

IP 240 Positioning
Fig. 10-22. Location of the Reference Point on Reference Point Approach
Counting
pulses
Positive direction of travel
Actual value when
NVER=0
NVER=20
Status bit
SYNC
HASY
control
bit
IN signal
Acquiring of the preliminary
contact signal by the module
firmware
t
2
t
1
t
3
Z pulse
t
1
: max. 6.5 ms t
2
: max. 6.5 ms t
3
: min. 6.5 ms t
4
: min. 6.5 ms
t
4
Reference point
. . . . . . 0 1 . . . 100
. . . . . . 20 21 . . . 120
As the preliminary contact signal is evaluated over the IP 240 module firmware, care must be
taken that acquisition of the signal edges is delayed by t
1
and t
2
. Moreover, time value t
3
must be
carefully observed.
After synchronization, the next zero mark must not occur for at least 6.5 ms (t
4
). If this is not
observed, the actual value may be synchronized again.
Using the control bits for reference point approach
• Control bit HASY (HArdware-controlled SYnchronization) is used to select a reference point
approach.
When HASY = 1 the channel is set to ”reference point approach” mode
When HASY = 0 the reference point approach can be exited or aborted following syn-
chronization
• The FREI control bit is used to enable the IP outputs at a supraordinate level
When FREI = 0 the outputs for the channel are disabled
When FREI = 1 the outputs for the channel are enabled
• The HAND control bit is used to specify whether the IP outputs are to be controlled by the IP
240 module firmware during reference point approach or whether the outputs are to be
switched as prescribed by the S5 CPU.
When HAND = 0 the channel's outputs are controlled by the module firmware
When HAND = 1 the outputs are switched as prescribed by control bits DA1S and DA2S
• Control bits DA1S and DA2S are used to control switching of the IP outputs.
When DAnS = 0 output Dn is reset
When DAnS = 1 output Dn is set
The permissible combinations of DA1S and DA2S depend on configuring parameter DAV, and
are checked by the module firmware.
EWA 4NEB 811 6120-02a 10-39