Modbus Communications (continued)
Network/Modbus
®
Communications 95
Integer DDC system receives
None
Room 1 Supply Flow Output
Room 1 Exhaust Flow Output
Anteroom Pressure Output
Room 1 Temperature Control
If Pressure: Displayed in in. W.C.
Host DDC system must divide value by
100 to report pressure correctly
If Flow: Displayed in CFM
If Control: Displayed in % Open
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
20
Normal
Room 1 Negative Low Alarm
Room 1 Negative High Alarm
Room 1 Positive Low Alarm
Room 1 Positive High Alarm
Low Exhaust Alarm
Low Supply Alarm
Low Temperature Alarm
High Temperature Alarm
Low RH Alarm
High RH Alarm
Anteroom Negative Low Alarm
Anteroom Negative High Alarm
Anteroom Positive Low Alarm
Anteroom Positive High Alarm
Data Error
EXAMPLE of 06 Write Single Register function format:
This example changes the negative low alarm set point to 0.00060 in. W.C.
QUERY RESPONSE
Field Name (Hex) Field Name (Hex)
Slave Address 01 Slave Address 01
Function 06 Function 06
Starting Address Hi 00 Starting Address Hi 00
Starting Address Lo 11 Starting Address Lo 11
Data Value (High) 05 Error Check (CRC) --
Data Value (Low) DC
Error Check (CRC) --