Danfoss VLT5000 SyncPos Operating Instructions Manual page 201

67 MENCODERTYPE
This parameter determines the type of master
encoder: incremental or absolute encoder.
Errors can occur when a linear absolute encoder is
used. A possible jump in the position data can be
detected with the encoder types "3" and "4", as
long as it is larger than the encoder resolution/2.
The correction is made by means of an artificial
position value which is calculated from the last
velocity. If the disruption is present for more than 100
read-outs (> 100 ms), no further corrections are
made, which will then in fact lead to a tolerated
position error exceeded.
The total number of disruptions that have occured
will be stored in an internal variable which can be
read out via SYSVAR[16].
It is possible to simulate a master by means of
APOSS command with the encoder type "6", for
example when the master position is read via the
bus. The simulated master positions are set and
read with the system variable SYSVAR[4105].
Content
Type of encoder for master encoder
Parameter Group
Axis parameter encoder AXE
CAM-Editor: index card encoder
Value range
0 ... 2 and 6 and 100 ... 102
0 = Incremental encoder
1 = Absolute encoder, standard ca. 262 kHz
2 = Absolute encoder, ca. 105 kHz
6 = The master position is not read by the enco-
der; instead, it is set with the system variable
SYSVAR[4105].
100 ... 102 = like 0 ... 2, however, hardware
monitoring of the encoder will be activated.
Error 92 will be issued in case of open or
short circuit.
NB!
With absolute encoders the following
commands can not be used: DEF ORIGIN,
HOME, INDEX and WAITNDX.
NB!
The following commands can only be used
with absolute encoders if external markers
are used: IPOS, MIPOS
200
Programmable SyncPos motion controller
68 SYNCMWI NM
The Marker Window Master Marker Window Master Marker Window Master Marker Window Master SYNCMWINM shows Marker Window Master
how large the permitted tolerance for the occur-
rence of the markers is.
With the works setting "0" the window is not moni-
tored, which means that it is always synchronized
to the next marker even if this has a considerably
larger interval.
At every other setting only those markers are accep-
ted which are within the window. If there is no
marker within the tolerance window the correspon-
ding flag (SYNCSTAT) is set and no marker correc-
tion takes place. The corresponding other marker is
also ignored and only corrected the next time – i.e.
no catching up to the next marker.
When SYNCM (or SYNCCSTART) is started the
monitoring only begins when the first marker has
been found.
Content
Tolerance window for marker monitoring
Parameter Group
Axis parameter Synchronization AXS
CAM-Editor: index card Synchron.
Unit
q c
or in CAM mode: MU
★ 0
Value range
0 ... MLONG or. max. Marker interval
SYNCMPULSM (58)
0 =
1 ... MLONG =
NB!
Changes of the parameter will become active
immediately – not only after the next SYNCM
command.
Sample
Marker interval SYNCMPULSM = 30000
Tolerance window SYNCMWINM = 1000
Only one marker within an interval of 29000 to
31000 is accepted.
MG. 1 0.J8.02 – VLT is a registered Danfoss trade mark
★ 0
The window is not monitored.
Only one marker is accepted
within the window. If no marker
is within the tolerance window,
the corresponding flag
(SYNCSTAT) is set and no
marker correction carried out.
This flag can be reset with an
interrupt (ON STATBIT).