Vaisala GML20T User Manual

GML20T LonWorks

module

MOUNTING AND INSTALLATION

The GML20T LonWorks® interface module enables communication between a LonWorks® network and a GMW21 transmitter over a twisted pair. The carbon dioxide is measured by a GMW21 transmitter and the temperature by the GML20T module itself.

1. Open the transmitter cover and remove the jumper from the pin connector at the center of the circuit board.

2. Pull the two network wires through the hole at the bottom of the housing. When connecting them to the screw terminal marked 'NET' of the GML20T, hold the module in one hand and make connections with the other (see Figure 1). The polarity can be freely selected. Note that as all NDIR transmitters consume power, an additional power supply is always needed. Check that the nominal 24 V supply is connected between terminals + and - on the transmitter's mother board. Analogue output signals can be used simultaneously with the LonWorks® module.

Figure 1: Hold the module in hand while connecting the wires

3. Install the module on the 2- and 5-pin connectors as indicated in Figure 2. Make sure

that the wires are between the module and the transmitter board before pressing the module in place.

Figure 2: Installing the GML20T module

GML20T LonWorks

module

4. Configure the transmitter using a suitable installation software (an external interface file

is also available as an option). The GML20T module has a service button for easy installation. A Wink message lights the service led up for approximately 5 seconds. During normal operation, the LED indicates the following:

dark = the transmitter configuration and operation are in order lit = there is something wrong with the transmitter blinking = the transmitter has not been configured (delivered in this mode)

5. Close the transmitter cover.

NETWORK VARIABLES TECHNICAL DATA

LonWorks® interoperable Twisted pair free topology

network type TP/FT-10 at 78 kbs

Additional two wires needed for

powering the transmitter

Can be connected to both

powered and non-powered networks

External interface (.xif) file

available on request (part no. 19748GM)

Temperature measurement

accuracy ±0.5°C

Temperature measurement range

0…+45°C

Warm-up time 30 min

GUARANTEE

Vaisala issues a guarantee for the material and workmanship of this product under normal operating conditions for one (1) year from the date of delivery. Exceptional operating conditions, damage due to careless handling and misapplication will void the guarantee.