10
IM 689-2
Figure 3. BACdrop Application with a MicroTech Supervisory Controller (Level-2 BACdrop)
Chiller
Level 2
MicroTech
Up to 63 MicroTech
controllers per BACdrop
BACnet BAS
by others
BACnet on ISO 8802-3 (Ethernet), 10BaseT
MicroTech
BACdrop
(level 2)
Level 1
Chiller
Chiller
Main "front end"
PC for BAS
CSC
Chiller
MicroTech network (RS-485)
All data requests from BACnet BAS to
MicroTech level-2 controllers are routed
through level-1 MicroTech controller
Monitor Software and BACdrop
In general, MicroTech Monitor™ software should
not
be used in a BACdrop network—except
perhaps for temporary troubleshooting purposes. A PC containing Monitor software can be directly
connected to port A (TTY) of any MicroTech controller for access to that controller only. (The
BACdrop Setup Wizard is also capable of this, although its capabilities are more limited.)
In a
BACnet BAS that is integrated with a MicroTech network via BACdrop, the user interface software
for the main “front end” PC should always be provided by the systems integration company.
When the BACdrop gateway is level 1 (see Figure 2 above), communications between the PC
containing Monitor software and other MicroTech controllers on the network is physically
impossible. Only the MicroTech controller that the PC is directly connected to can be communicated
with. This excludes the BACdrop gateway itself—Monitor software cannot be used to communicate
with the BACdrop gateway by any means. (The BACdrop Setup Wizard allows this.)
When the BACdrop is level 2 (see Figure 3 above), communications between the PC containing
Monitor software and other MicroTech controllers on the network is possible, but it will severely
affect the data transmission rates through the BACdrop gateway.
We do not recommend such an
application.