Atest Gaz MOD CNV PK420, Руководство пользователя

Страница: 5 / 16

www.atestgaz.pl
1 General information
The Control Unit Module MOD CNV PK420 enables extension of an existing Gas Safety System and is
meant to convert an On/Off signals received from relay outputs of the Control Unit into a discrete signal
4..20 mA, whereas an active signal with the highest priority is transferred to the output of the module (See
Table 2).
The unit produces a discrete output signal as an electric current within the range from 4 to 20 mA that
enables wiring a Control Unit Module with a relay output to a Control System or a Control Unit that has an
analog input 4..20 mA. Such a solution enables:
monitoring of a transmission line, where failures (shorts, line breaks) are distinguished from
regular operation and an emergency alarm (see Figure 4),
transmission of an input signal for further processing by a Central Control Unit (e.g. EcoAlpa, Alpa
P17, MOD LED8, etc.).
For normal operation of the unit the PK FAILURE output of a control device wired to the MOD CNV PK420
module must be inverted to match the logic levels adopted for the solution (see Table 2 and Figures 1 and
4) when relevant inputs of the signal converter are closed, the module produces an output signal with the
appropriate current amperage:
Status of contacts at the
inputs to the MOD CNV
PK420 module
Output current of the
converter module
Meaning for Control Unit of
the Alpa series
Order of priorities
‘+’ closed to ‘AL’ 15 mA ALARM 1 (highest)
‘+’ closed to ‘OS’ 10 mA WARNING 2
All contact open 2.5 mA FAILURE 3
‘+’ closed to ‘P’ 5 mA OPERATION 4 (lowest)
Table 2: Specification of output signals produced by the Signal Converter Module MOD CNV PK420
Figure 1: Switching of contact for an inverted FAILURE relay output of the control unit driving the signal
converter
s. 5|9
User Manual: POD-016-ENG R01
COM
NO
NC
NO FAILURE
COM
NO
NC
FAILURE