Operating Instructions
Chapter 4 - Parameters and Menu Structure
I/O and Hardware (M5)
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Siemens Industry, Inc.
Siemens BT300 HVAC Drive
DPD01809
Smart Infrastructure
2019-05-29
3. Select: Main Menu > I/O and Hardware (M5) > RS-485 (M5.8) > BACnet MSTP (M5.8.3) >
Parameters (M5.8.3.1) > Baud Rate (P5.8.3.1.1) > Edit.
4. Enter the desired baud rate and press the button.
5. Select: Main Menu > I/O and Hardware (M5) > RS-485 (M5.8) > BACnet MSTP (M5.8.3) >
Parameters (M5.8.3.1) > MAC Address (P5.8.3.1.2) > Edit.
6. Enter the desired network device address and press the button.
7. Select: Main Menu > I/O and Hardware (M5) > RS-485 (M5.8) > BACnet MSTP (M5.8.3) >
Parameters (M5.8.3.1) > Instance Number (P5.8.3.1.3) > Edit.
8. Enter the desired instance number and press the button. (Used when a BACnet MS/TP to BACnet
IP router is on the network.)
9. Select: Main Menu > I/O and Hardware (M5) > RS-485 (M5.8) > BACnet MSTP (M5.8.3) >
Parameters (M5.8.3.1) > Comm. Timeout (P5.8.3.1.5) > Edit.
10. Enter the desired time for drive to monitor for a communications loss and press the button. A value
of 0 disables this monitoring.
For commanding Start/Stop and Speed Reference using the BACnet MS/TP protocol, complete the following
steps:
1. Complete all settings required for Monitoring as listed above.
2. Set Ctrl. Place Auto (P3.2.1) to a value of FieldbusCTRL.
For commanding Start/Stop through the BACnet MS/TP protocol and Speed Reference through an Analog
Input, complete the following changes:
1. Complete all settings required for Monitoring as listed above.
2. Set Ctrl. Place Auto (P3.2.1) to a value of FieldbusCTRL.
3. Set FieldbusCtrl Ref (P3.3.9) to a value of AI1 or AI2 (depending upon which AI is in use).
For commanding Start/Stop through a Digital Input and Speed Reference through the BACnet MS/TP
protocol, complete the following steps:
1. Complete all settings required for Monitoring as listed above.
2. Set Ctrl. Place Auto (P3.2.1) to a value of I/O Control.
3. Set I/O A Ctrl Ref (P3.3.3) to a value of Fieldbus.
P1 FLN (M5.8.3)
The Siemens P1 FLN fieldbus communications protocol is used by Siemens and others to connect terminal
unit controllers to supervisory controllers. It is open to any manufacturer and widely used in the HVAC
controls industry.
The physical characteristics of the P1 FLN bus is an RS-485 three-wire, with a maximum of 96 devices over a
4,000 foot (1219 m) distance, running at 4800 bps. The RS-485 interface is a half-duplex system. The transfer
cable is supported as a Shielded Twisted Pair, type Belden 98410 or similar. However, on variable speed
drives, the third wire (shield) is not terminated to the drive itself.