Contrec 515, Operation Manual

Page: 23 / 92

Installation
515 HC04 - 8 June 2007 15
Connect RTD inputs as shown in Figure 8.
Figure 8 RTD Connection
Analog Inputs 1 and 2 (AINP1 / AINP2) are available for RTD connection.
Excitation terminal 2 (pin 5) must be used in conjunction with AINP1.
Excitation terminal 3 (pin 6) must be used in conjunction with AINP2.
It is possible to use two-wire or three-wire RTDs. However, four wires must
be taken to the RTD, with the signal and current wires joined as close to the
RTD as possible.
Note: The RTD has no polarity and can be connected in either direction.
However, the excitation and the positive analog input must be
connected to one side of the RTD. Similarly, the Signal Ground and
the negative analog input must be connected to the other side of the
RTD.
Logic Input Connection
These input(s) are designed to be connected to CMOS, TTL, open collector
signals or a voltage free contact switch. A minimum activation time of
300ms is required to guarantee reading of an input.
It is possible to read the status of all the logic inputs via a Modbus register
even if they are not used for a control purpose in the application.
+
-
-
+
+
3
Excitation V (EXC V)
Signal Ground
18
Shield
Analog Input (AINPn)
Analog Input (AINPn)
RTD