User Guide
Table Of Contents
- 1. General
- 2. LonWorks C4 Option Board Technical Data
- 3. LonWorks Fieldbus C4 Option Board Layout and Connections
- 4. Installation of Honeywell NX LonWorks C4 Option Board
- 5. Commissioning
- 6. LonWorks Interface
- 7. Fault Tracking
- 8. Appendix 1
- 9. General Info
- 10. BACnet CJ Option Board Technical data
- 11. Bacnet Fieldbus CJ Option Board Layout and Connections
- 12. Grounding Cable Shield
- 13. Led Indications
- 14. Installation of Honeywell NX BACnet CJ Option Board
- 15. Commissioning
- 16. Fault Tracking
Honeywell BACnet Grounding Cable Shield 39
12.3 Bus Terminal Resistors
Figure 22. Using jumper X4 to set the bus termination
If Honeywell is the last device of the fieldbus line the bus termination must be set. Use
jumper X4 (ON position). See Figure 22.
Note: Jumper X1 is only used when D9 type connector is assembled (Not used with BACnet
protocol)
12.4 Bus Biasing
Bus biasing is required to ensure faultless communication between devices at RS-485 bus.
Bus biasing makes sure that the bus state is at proper potential when no device is
transmitting. Without biasing, faulty messages can be detected when the bus is in idle state.
RS-485 bus state should be neather +0,200..+7V or –0,200..-7V. Illegal bus state is
<200mV..-200mV.
Number of nodes Bias resistance
2-5 1.8 kohm
5-10 2.7 kohm
11-20 12 kohm
21-30 18 kohm
31-40 27 kohm
Table 19. Bias resistor size vs number of node