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Home and Latch conflict

Valid for S400, S600

Problem

On a machine the homing procedure NREF 5 (move to the next zero-mark of the feedback unit) is started cyclic. 

The Position latch (digital input setting IN2MODE 26 with trigger variable IN2TRIG 5) is used also. If the digital input signal for input 2 is given during a homing cycle, the axis will not go to the reference position – the position is latched and motion task no 5 is started.

Solution

The Homing is started by the command buffer and during the homing cycle the trigger variable of input 2 is set to 0.The settings are:

IN3MODE 30 Command Buffer 1 A positive or negative edge on the input starts a command buffer. This command buffer contains separate ASCII objects, that are separated with semicolon (;).When the drive is switched on, the Command buffer is set automatically started to the corresponding state of the input.
INHCMD IN2TRIG 0; WAIT 50; MH The command buffer for the positive edge is INHCMD In case of input 2 gets a signal with rising edge it will not start a motion task – a delay time of 50 ms is executed – the reference motion task is starting
INLCMD IN2TRIG 5 the command buffer for the negative edge is INLCMD. In case of input 2 gets a signal with falling edge it starts motion task no. 5
SAVE Save data to EEPROM  
COLDSTART Restart the drive and activate the new configuration