Danfoss MCO 305 Design Manual page 121

MCO 305 Design Guide
IPOS
Summary
Syntax
Return Value
Description
Command Group
Cross Index
Syntax Example
Sample
__ Software Reference __
Queries last index or marker position of the slave
res = IPOS
res = last slave position (index or marker) absolute to actual zero point.
The position input is made in user units (UU) and corresponds in the standard
setting (parameter 32-12 UU Numerator and 32-11 UU Denominator = 1) to the
number of qc.
The command IPOS returns the last index or marker position of the slave absolute
to the current zero point.
NB!:
If a temporary zero point, set and activated via SET ORIGIN, exists, then the
position is respective to this zero point
The configuration of IPOS, that is whether the slave index- or marker position
(= controlled drive) is returned, is done via the par. 33-20 Slave Marker Type.
NB!:
The trigger signal for the marker position has to be connected mandatory to the
input 6.
The position value in IPOS is accurate to +/- 1qc. In opposite to the position infor-
mation in APOS, which is just updated in a controller cycle of typically 1 ms, the
actual position value is hardware stored in real time a buffer (in an internal
processor register), when the configured signal is high. Then it will be copied in the
system variable IPOS.
If simultaneously to the marker position an interrupt is initiated (ON INT 6 GOSUB
...) and within this interrupt it is operated with IPOS, you should use before IPOS
reading a delay of 2 milliseconds (DELAY 2) within the interrupt subroutine. So it
can be ensured, that the latched position value is already complete copied in the
system variable IPOS and that not be taken an old value. See also sample.
NB!:
The command IPOS can not be used:
– with absolute encoders (see par. 32-00 Incremental Signal Type)
– when Parameter 32-50 is set to [3] – Motor Control.
I/O
CPOS, DEF ORIGIN, SET ORIGIN, POSA, POSR, MIPOS, ON INT
Parameters: 32-12 User Unit Numerator, 32-11 User Unit Denominator, 33-20
Slave Marker Type
PRINT IPOS /* queries last index position and display on PC */
ON INT 6 GOSUB slave_int
SET SYNCMTYPS 2 // Definition of IPOS latching on positive edge at input 6
CVEL 10 // Start moving
CSTART // Endless-Loop
mainloop: // ...
GOTO mainloop
SUBMAINPROG
®
MG.33.L4.02 – VLT is a registered Danfoss trademark
// Definition interrupt handler
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