Chapter 18: Multiplexer Setup and Operation
Introduction
ValVue can support multiple SVI devices using a MTL HART multiplexer that allows a user to monitor
and operate several SVI devices from a single computer.
The MTL 4840 HART maintenance system is one of the most widely used multiplexer for communicating
with HART instruments. Connecting a computer serial port with a RS232/RS485 converter, the multi-
plexer is capable of supporting up to 31 nodes, each with the capability of supporting up to 16 sub
nodes. Each sub node can control 16 loops. Therefore the multiplexer provides the potential to com-
municate with a maximum of 7936 HART loops, i.e., 31 (nodes) x 16 (sub nodes) x 16 (loops) using one
computer interface. Additionally, the multiplexer supports the multidrop connection of HART devices on
a single loop. Therefore, using the multidrop feature it is possible to expended capacity of a system
beyond 7936 HART devices.
For more information regarding the MTL multiplexer, refer to the manufacturer's documents and ValVue
Mux Connection Guide.
ValVue Multiplexer Options
Using the multiplexer version of ValVue and the MTL multiplexer communicating and monitoring of many
SVIs and other HART devices is possible. After starting up and login on to the ValVue program, the
Select Device Window is displayed and provides options to setup the multiplexer.
Options Window Setup
The first step to setup the multiplexer is clicking the Options button in the Select Device Window. The
Options window (figure 61) allows the user to set options that relate to HART and multiplexer communi-
cations.
101
Figure 61. Options Setup
Window