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Projecting with TwinCAT System Manager V2.10
TR-Electronic GmbH 2016, All Rights Reserved
Printed in the Federal Republic of Germany
Page 128 of 153
TR-EMO-BA-GB-0022 v03
09/29/2020
The resulting input signals, that have been transferred remotely from the master by
SDOs or RPDOs, can be read back by 0x60FD, just like the real inputs:
0x2F04:01 = 0
// -> The "Digital Input AND Mask" blocks the actual digital input bits.
0x2F04:02 = <written remote digital inputs>
// -> The "Digital Input XOR Mask" negates single bits.
0x60FD = <resulting digital inputs> = <XOR mask> XOR (<AND mask> AND <actual
digital inputs>)
// The evaluated "Digital Inputs" show the remotely transferred digital inputs just like
real inputs.
10.6.4 Operation of the Digital Inputs as Limit Switches
The digital input bits 2
0
and 2
1
work as lower = negative and upper = positive
hardware limit switches in the "Profile Velocity Mode".
Since the software version "V1.1 20-September-2016" they also work in the "Profile
Position Mode".
In other modes they have no effect, except in the "Homing Mode" according to the
DS402 drive profile.
Effect of the hardware limit switches:
If the input bit for the lower limit switch is set and the drive moves to descending
positions, it stops.
If the input bit for the upper limit switch is set and the drive moves to ascending
positions, it stops.
If both input bits are set, the drive can't move at all.
Thus it is still possible to return into the allowed range. Commands by the control word
with target values, that would move the drive into the wrong direction, are ignored.
Important hints:
Bit 2
7
of the object 0x607E reverses the polarity of the position.
Bit 2
6
of the object 0x607E reverses the polarity of the velocity.
The hardware limit switches always refer to the position. Therefore the lower switch
must be located at a lower position than the upper one. If this is reversed, try
switching the polarity flag of the position.
The hardware limit switches and homing work properly with any combination of the
polarity flags. However it is recommended to set the polarity flags for the position
and the velocity equal. Otherwise the indicated values may be confusing: The
velocity will be negative, if the position values are ascending, and the other way
round.
Since the software version "V1.1 7-December-2016" the limit switches use the
"Homing Acceleration" 0x609A as deceleration, when they stop the drive, because
the homing mode already links that parameter to the digital inputs.
Before that version the limit switches used the stop deceleration, which is however
not related to the digital inputs in any way.