SBC PCD2 Series - PCD3.H150, SSI Interface Module for Absolute Encoder

Saia-Burgess Controls AG
Manual I/O-modules for PCD1 │ PCD2 series │ Document 27-600 – Release ENG09 │ 2019-05-01
6-119
I/O modules PCD3
PCD3.H150
6
6.17.3 PCD3.H150, SSI interface module for absolute encoder
Application
The PCD3.H150 module is an interface module for the SSI standard. (SSI = Syn-
chronous Serial Interface). The SSI standard is used with most absolute encoders.
DetailsofSSIspecicationscanbeobtainedfromtheSTEGMANNcompany’s
brochure: “SSI-Technical Information”.
The hardware consists of an RS-422 port for the SSI interface and 4 general-
purposedigitaloutputs.FunctionalityisprovidedbyanFPGA(eldprogrammable
gate array).
Technical data
Resolution: congurablefor8…29databitsand0…2controlbits
Clock frequency: congurablefor100kHz,200kHz,300kHz
and500kHz(inputlterdesignedfor500kHz)
Frequency has to be selected de-
pending on cable length:
Cable length Frequency
< 50 m max. 500 kHz
< 100 m max. 300 kHz
< 200 m max. 200 kHz
< 400 m max. 100 kHz
Data code: congurable-Grayorbinary
Read mode: Normal (single read). Ring mode: ‘double read and compare’
(not all encoders support this function)
O󰀨setposition: Ano󰀨setcanbedenedwheninitializingthePCD3.H150.The
denedo󰀨setisalwayssubtractedintheFBs.The‘SetZero’
commandalsousesthiso󰀨setregister.
Execution time: typically 1.5 ms for reading the SSI value
Cable break detection: detected with the FB ‘timeout’ (10 ms)
Flags ‘fTimeout’, (for cable break, encoder fault or incorrect
addressing)
‘fPar_Err’, (if a wrong FB parameter is sent)
‘fRing_err’ (if compare error in ‘double read’)
SSI interface
1 input for SSI data RS-422, electrically isolated
1 output for SSI clock RS-422, electrically connected,
as the encoder input is normally isolated
Digital outputs
Number of outputs:
Terminal 4 = 012:
Terminal 5 = O13:
Terminal 6 = O14:
Terminal 7 = O15:
4
Speed high
Speed low
Dir + positive direction
Dir - negative
Switching capacity: 0.5A each in the range 10…32 VDC, residual ripple max. 10%
Short circuit protection: yes, I
max
=1.5 A
Electrical isolation: no
Voltage drop: max. 0.3 V at 0.5 A
Circuit type:
positive switching
Output delay: typ.50 µs, max. 100 µs under ohmic load
Power supply
Internal current consumption:
(from +5 V bus)
25 mA
Internal current consumption:
(from V+ bus)
0 mA
External current consumption: For all outputs max. 2 A,
ripple max. 10 %