22
IM620-1
Cable Specifications
The cable for the digital outputs must meet the following minimum requirements: twisted, shielded pair
with drain wire, 300 V, 60° C, 20 AWG, polyethylene insulated, with a PVC outer jacket. Depending on
the application, either two conductors (Belden 8762 or equivalent) or three conductors (Belden 8772 or
equivalent) are required. Note that some local codes or applications may require the use of plenum
rate cable. Do not install the cable in the same conduit with power wiring.
Wiring Instructions
The following wiring instructions explain how to connect a digital output to the MAG Panel.
Use the following procedure to connect a digital output to the MAG Panel.
1.
Remove power from the panel by pressing CB1 to the OFF position.
2.
Connect a wire from screw terminal #1 on the Output Board to the digital output device.
3.
Connect a wire from screw terminal #2 on the Output Board to the digital output device.
4.
Repeat steps 1-3 for each digital output that needs connection to the MAG.
5.
Restore power to the panel by pressing CB1 to the ON position.
Network Commissioning
The purpose of network commissioning is to establish and verify communications between a
MicroTech controller, MAG Panel(s), and absorption chillers. (It is not to establish and verify unit
operation.
Addressing the Controllers
For network communications to occur, each controller in the network must have a unique network
address. A controller’s hex switch setting defines its network address. For more on hex switch
settings, see “Microprocessor Control Board” in the “Component Data” section of this manual.
The Network Connect MAG Network
The Network Connect MAG Network includes a Network Master Panel (NMP), an Open Protocol
Master Panel (OPM), or other high level MicroTech control panel plus two or more MAG panels. Each
MAG Panel has one associated absorption chiller unit controller. It may also contain other level-2 unit
or auxiliary controllers that could be accessed with a PC via network communications. In this case, the
NMP, OPM, or other high level MicroTech control panel is the level-1 controller. The MAG Panels are
level-2 controllers along with any other unit or auxiliary controllers. Since the NMP, OPM, or other
high level control panel is a level-1, its hex switch setting must be 00. The hex switch settings of the
MAG Panels and other level-2 controllers must start at 01 and continue consecutively to a maximum of
40 (decimal 64). There must be no gaps in the sequence and no duplicate settings. As long as these
rules are followed, a level-2 controller’s hex switches can be set to any value. To keep the system
simple, you should consider addressing the NMP, OPM, or other high level control panel and MAG
Panels according to their designations.
For example, assume that a MicroTech network includes an NMP, two MAG Panels, and two
absorption chillers. One possible addressing scheme is as follows:
Hex Switch Setting
Controller
00
NMP
01
MAG Panel #1
02
MAG Panel #2
Note:
The absorption chillers have non-MicroTech unit controllers; therefore, they are not included
in the network addressing scheme. Each absorption chiller unit controller is directly connected to a
MAG Panel.
