SBC PCD2 Series - Page 109

Saia-Burgess Controls AG
Manual I/O-modules for PCD1 │ PCD2 series │ Document 27-600 – Release ENG09 │ 2019-05-01
5-100
I/O modules PCD1|PCD2
PCD2.W525 Combined analogue input/output module with galvanic isolation
5
Function
Power Supply
PCD2.W525 has to be supplied externally! This power supply is galvanically iso-
lated to both, the Saia PCD
®
and the I/Os of W525. Furthermore, the design allows
using the same power supply for the Saia PCD
®
and for W525 without loosing the
galvanicisolation.Theseschematicsshowthedi󰀨erentzonesofisolation:
Timing
● Inputs
○ Internally,W525nishesacquiringevery2msanewvalueforevery
input channel
○ This value is always ready to be read by the Saia PCD
®
.
○ Dependent on the Saia PCD
®
speed, the transmission time of a single
  16-Bitscaledvalue(ofasingleinputchannel)takestypically100μs(on
  aPCD2.M480)or600μs(onaPCD2.M170)
● Outputs
○ Internally, W525 outputs the last received output value from Saia PCD
®
with a maximum delay of 2 ms.
○ Dependent on the Saia PCD
®
speed, the transmission time of a single
  16-Bitscaledoutputvaluetakestypically100μs(onaPCD2.M480)or
  600μs(onaPCD2.M170).
Filter
● Inputs
 Therearetwofactors,whichhavelteringe󰀨ectstotheacquiredvalues:
○ Thebasehardwarelterwithatimeconstantof2ms.Thislterattenu-
  atestheinputsignalby6dB/decadeatacut-o󰀨frequencyof80Hz.
○ Thesecondinuenceiscausedbysoftwareandresultsinadelayof
  theacquiredvaluefor2mswithanotchltercharacteristicsat500Hzif
  nosoftwarebased50Hz/60Hzlterisselected.