SBC PCD2 Series User Manual

Saia-Burgess Controls AG
Manual I/O-modules for PCD1 │ PCD2 series │ Document 27-600 – Release ENG09 │ 2019-05-01
8-10
PCD2.W380 & PCD3.W380
PCD2/3.W380,8analogcongurableinputs
8
8.1.8 Input protections
The design supports an input voltage between –20 V to +20 V in all the modes
of measurement. It can be considered a passive protection. Higher values can
damage the module. For voltages higher than ±13 V a current passes through the
circuit. It can be calculated approximately: I
overvoltage
=(Vin–13V)/225Ω.
Inthissituation,thevaluesmeasuredontheotherchannelscanbefalsied.
Active protections are implemented for current measurements, but in all conditions
the input voltage must be lower than ±20 V. The bit corresponding to the channel
is set to ‘1’ in the register “ModuleErrors” when the protection is enabled.
8.1.8.1 Current measuring range
225
Input
I < 30 mA
Switch
closed
If current mode is chosen the measuring
shunt is connected to ground through the
switch as shown in the picture on the left.
In case the current is higher than 30 mA¹
the switch opens to protect the measuring
shunt. For voltage lower than ±13 V on the
opened input the current will be kept lower
than 1 mA. If the voltage on the opened
input rises above +/-13 V the current can be
approximately calculated using the formula:
I
overvoltage
=(Vin–13V)/225Ω
Care should be taken to keep input voltage
below ±20 V.
225
Vz = 13 V
Input
I > 30 mA
Switch
opened
¹ HW version ‘A’ and ‘A1’ : Limit = ±24 mA

SBC PCD2 Series Specifications

General

Brand	SBC
Model	PCD2 Series
Category	I/O Systems
Language	English