AERCO Control System (ACS)
APPENDIX H:
ACS Modbus Address Assignments
Page 128 of 139
AERCO International, Inc.
•
100 Oritani Dr.
•
Blauvelt, New York 10913
11/22/2017
GF-131
Phone: 800-526-0288
OMM-0081_0F
H.2 ACS CONTROLLER STANDARD HOLDING REGISTER ASSIGNMENTS
The Holding Register address assignments for the ACS are listed in Table H-2 which follows. Unless
otherwise specified, all Holding Register Menu items are Read/Write (R/W).
TABLE H2: ACS Standard Holding Register Address Mapping
Modbus Data
Address
Decimal (Hex)
Menu Item
Units and Range
Default/
Comments
0 (0x0000)
thru
3 (0x0003)
(Reserved)
4 (0x0004)
Net Header Set Temp
40 to 220°F
Valid when Hdr Set
Mode=Remote Setpt and
Remote Signal = Network
5 (0x0005)
System Start Temp
32 to 120°F
Default = 70°F
6 (0x0006)
System Start Option
0 or 1
0 = Temp Only,
1 = Temp and Load
Default = 0
7 (0x0007)
Manual Hdr Set Temp/Internal
Setpt
40 to 220°F
Default = 160°F
8 (0x0008)
Bldg Ref Temp
40 to 220°F
Default = 70°F
9 (0x0009)
Not Applicable
10 (0x000A)
Not Applicable
11 (0x000B)
Reset Ratio
0.3 to 3.0
(0.1 increments),
Default = 1.2
(Value x 10)
12 (0x000C)
Max Header Temp
40 to 220°F
Default = 200°F
13 (0x000D)
Min Header Temp
40 to 220°F
Default = 40°F
14 (0x000E)
Start Percent
25 to 100%
Default = 20%
15 (0x000F)
Stop Percent
10 to 45%
Default = 16%
16 (0x0010)
Integral Gain
0.00 to 9.99 Rep/Min
(in 0.01 increments
Default = 0.15 Rep/Min
(Value x 100)
17 (0x0011)
Header Set Mode
0, 1, or 2
0 = Constant Setpt
1 = In/Outdoor Reset
2 = Remote Setpt
Default = 0
(Constant Setpt))
18 (0x0012)
Derivative Gain
-2.00 to 2.00
(0.00 increments)
Default = 0.15
(Value x 100)
19 (0x0013)
Header Temp Bandwidth
5 to 120°F
Default = 70°F