Specifications

LonWorks

Options for GML 20 and 20T

Series CO

Transmitters

SIGNIFICANT SAVINGS

Vaisala's GML 20 and GML 20T are interface modules

for distributing signals from GM 20 series transmitters

digitally to a LonWorks® network over a twisted pair.

The GML 20 module distributes CO

signals; the GML

20T module distributes both CO

and temperature

signals. The GML 20T module can be used with the

GMW 21 transmitter only. The use of these modules

and GM 20 series transmitters with a LonWorks®

networked control system contributes to considerable

savings in cabling, installation and maintenance costs.

INTELLIGENT LonTalk

PROTOCOL

In a LonWorks® network, devices called nodes

communicate with each other using the LonTalk®

protocol. Every node consists of a Neuron® chip and

a transceiver. The Neuron® chip is a microprocessor

which contains an application program and

LonTalk® protocol. The transceiver adapts the

Neuron® chip into the hardware environment used.

The nodes communicate with each other, sending

messages containing the value of the desired vari-

ables.

With Vaisala modules, these variables are CO

(GML

20) or CO

and temperature (GML 20T). Some

network variables are so-called configuration vari-

ables, which are used to define the behavior of the

node. With the GML 20 and GML 20T, they are used

to designate how much the temperature and/or

carbon dioxide level must change before a measured

value is sent again.

GML 20 GML 20T