Vaisala PR-23, PR-33 User Manual

IM-EN-MAOUT-B

User Guide

mA Output Unit System

for PR-23 and PR-33

1 Description

1

1 Description

The mA output unit is used to convert the standard ethernet signal from a PR-33 or a PR-23 refractometer sensor into a 4–20 mA output signal. The core of an output system consists of a CPU and 1 to 4 mA output unit modules, each with two independent galvanically isolated current outputs. The unit is powered with 24 VDC.

Figure 1.1 A CPU (PR-10952) with two output unit modules (PR-10922) on a DIN rail

1.1 Suggested configurations

ThemAoutputcanbeusedinseveraldifferentconfigurations. Therearetwoquestions which determine the modules required by the system:

•How many outputs are required?

•How is the system powered?

2	mA output instruction manual

EachmAoutputunit(PR-10922)hastwoindependentcurrentoutputs. Amaximumof four mA output modules can be connected to the CPU (PR-10952), to give a maximum ofeightcurrentoutputs. If, forexample, fiveoutputsarerequired, the systemconsists of one CPU and three mA output modules.

Ifthereisa24Vsupplyalreadyinstalledintothecontrolsystem,noseparatepowersupply is required. If a 24 V connection is not available, a mains power supply (PR-10951) can be used to supply the 24 VDC.

The following sections describe some typical PR-33 installations with mA outputs.

1.1.1 Single-sensor PR-33 system with mA outputs

•1 pc PR-33

•1 pc PR-10920, PoE switch (part of the PR-33 system)

•1 pc PR-10952, CPU unit for mA outputs

•1 pc PR-10922, mA output unit

•1 pc PR-10951, 24 V power supply for the PoE switch and the CPU

This configuration enables mA outputs for concentration and temperature for a single

PR-33, as there are two independent outputs in the mA output unit.

1.1.2 Three-sensor PR-33 system with mA outputs

•3 pcs PR-33

•1 pc PR-10920, PoE switch (part of the PR-33 system)

•1 pc PR-10952, CPU unit for mA outputs

•2 pcs PR-10922, mA output unit (gives a total of four outputs)

•1 pc PR-10951, 24 V power supply for the PoE switch and the CPU

This configuration gives three concentration mA outputs, one for each sensor. If the temperature outputs are required, an additional mA output unit (PR-10922) may be added to give a total of 6 mA outputs.

1 Description

3

1.1.3 Four-sensor PR-33 system with mA outputs

•4 pcs PR-33

•1 pc PR-10920, PoE switch (part of the PR-33 system)

•1 pc PR-10952, CPU unit for mA outputs

•2 pcs PR-10922, mA output unit (gives a total of four outputs)

•1 pc PR-10951, 24 V power supply for the PoE switch and the CPU

This configuration gives four concentration mA outputs, one for each sensor. If the temperature outputs are required, two additional mA output units (PR-10922) may be added to give a total of 8 mA outputs.

Mains		power

mA	outputs

PR-33-S	PR-33-S
PR-33-S	PR-33-S

	switch
PoE		supply
power				CPU
V			unit
+24	Output					unit
				output		unit
			mA		output
		Dual		mA
		Dual

Figure 1.2 Four-sensor system with in total 4 mA outputs

1.1.4 Two-sensor PR-23 system with remote mA outputs

•1 pc PR-23 DTR

•2 pcs PR-23 sensors

•1 pc PR-10952, CPU unit for mA outputs

•1 pc PR-10951, 24 V power supply for the CPU

•2 pcs PR-10922, mA output unit

A single PR-23 system may have two sensors connected to one transmitter (DTR). The DTR has two current outputs, but in some cases it is useful to have extra outputs or remote outputs.

4	mA output instruction manual

In the system above the DTR is connected to the mA output unit CPU (PR-10952) with across-overEthernetcablesothatnoEthernetswitchis required. ThetwomAoutput units give a total of four outputs so that both the concentration and the temperature can be indicated for both sensors.

If the Ethernet cable is replaced by a fiber connection, the distance between the DTR and the output unit may be up to several kilometers (miles).

ThesystemcanbeexpandedtoaccommodatemoreDTRsbyaddinganEthernetswitch and mA outputs as required.

For wiring instructions, please see chapter 2.