Data Sheet
14
Were the I
AO1
desired
is the desired value in mA.
Remember that the value written to the register should be truncated in order to fit in the 16bit register
(the value must be integer within 0 – 4095).
Connection of PT1000 to AO of Group 1
Alternative function of analogue output in Group 1 while set to current source is the measuring of
connected resistor. This feature is suitable for reading resistance of sensors, more specifically
temperature sensor Pt1000. Its connection is demonstrated in the following illustration.
Group 1 Analog output resistance measuring
For precise measurement of analog output, it is necessary to do a correction of read value with reference
voltage stored in the group processor with a help of the following formula and setting of output current
to for example 1 mA.
[V]
Where each of the variables is the value read from the corresponding registers. Conversion to
resistance is done with the following formula according to the set output current and measured
voltage.
2.4.8 Relay output connection
Relay outputs are to be connected to RoY.X and COM screw connectors and serve for switching two-
state components with either AC or DC voltage. COM screw connector serves as supply of switched
voltage for devices connected to the same connector. Screw connector of RoY.X serves for conducting
of switched voltage of the given relay output. Relays are connected in NO (normally opened) wiring thus
their output equals zero when switched off.
Corresponding indication LED diode on the front side of the device lights up when the output is switched
on. It is optimal to accomplish overload and short circuit protection through external circuit breaker
separately for each Relay output, or possibly for the whole RO group. Rated current and type of the