ADLINK PCI-8134A - Manual (Page 63)

Operations
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4.2
Motor Drive Interface
The PCI-8134/PCI-8134A provides the INP, ERC and ALM signals for
servomotor driver’s control interface. The INP and ALM are used for
feedback the servo driver’s status. The ERC is used to reset the servo
driver’s deviation counter under special conditions.
4.2.1 INP
Usually, servomotor driver with pulse train input has a deviation (position
error) counter to detect the deviation between the input pulse command and
feedback counter. The driver controls the motion of servomotor to minimize
the deviation until it becomes 0. Theoretically, the servomotor operates
with some time delay from command pulses. Accordingly, when the pulse
generator stops outputting pulses, the servomotor does not stop but keep
running until the deviation counter become zero. At this moment, the servo
driver sends out the in-position signal (INP) to the pulse generator to
indicate the motor stops running.
Usually, the PCI-8134/PCI-8134A stops outputting pulses upon completion
of outputting designated pulses. But by setting inp_enable parameter in
set_inp_logic() function, you can delay the completion of operation to the
time when the INP signal is turned on. Status of motion_done() and INT
signal are also delayed. That is, when performing under position control
mode, the completion of start_a_move(),
start_r_move(),
start_s_move()… functions are delayed until INP signal is turned ON.
However, EL or ALM signal or the completion of home return does not
cause the INP signal to delay the timing of completion. The INP signal may
be a pulse signal, of which the shortest width is 5 micro seconds.
The in-position function can be enable or disable. The input logic polarity
isalso programmable by software function:set_inp_logic(). The signal
status can be monitored by software function: get_io_status().
4.2.2 ALM
The ALM pin receives the alarm signal output from the servo driver. The
signal immediately stops the PCI-8134/PCI-8134A from generating pulses
or stops it after deceleration. If the ALM signal is in the ON status at the
start, the PCI-8134/PCI-8134A outputs the INT signal without generating