ADLINK PCI-8258 - Manual (Page 209)

Motion Control Theory 195
PCI-8254 / PCI-8258
4.11.2 Software Protection
The controller provides software protection mechanism of
software limit and position error protection.
4.11.2.1 Soft-limit Signal
Software limit functions almost the same as that of the hardware
limit with the exception that limit signal is generated by checking
location of each axis with the software limit function. There are the
same plus limit (PEL) and minus limit (MEL) signals. Steps of
using the software limit are described below:
1. Set up position of software limit with axis parameters
PRA_SPEL_POS and PRA_SMEL_POS shown in table
below.
2. Set up stop mode in response to limit signal. You can
select decelerating stop or immediate stop with axis
parameter PRA_EL_MODE (0x02) and PRA_SD_DEC
(0x07).
3. Start up software limit function with axis parameter
PRA_SPEL_EN (0x08) and PRA_SMEL_EN (0x09)
shown in table below.
Please run home operation to ensure limit position of the
coordinate system before the software limit function can be
started.
After the software limit function is initiated, you may use the
function library provided by the controller to display signal status.
This IO monitoring function is described below:
APS_motion_io_status ();
NO Define Description
02h PRA_EL_MODE
EL signal stop mode
See deceleration rate reference parameter,
PRA_SD_DEC, for deceleration stop mode:
07h PRA_SD_DEC Set up rate for deceleration stop
08h PRA_SPEL_EN Soft PEL switch
09h PRA_SMEL_EN Soft MEL switch
0Ah PRA_SPEL_POS Soft PEL position
0Bh PRA_SMEL_POS Soft MEL position