Modbus Read, Write and Override Parameters plus Exception Codes 
4/07  UDC2500 Universal Digital Controller Product Manual  209 
10.7.8 Control 
Table 10-16 lists all the register addresses and ranges or selections for the function 
prompts in Set-up Group Control. 
Table 10-16  Set-up Group – Control 
Parameter 
Description 
Register 
Address 
Data 
Type 
Access  Data Range or 
Enumerated Selection 
  Hex  Decimal       
Tuning 
Parameter 
Selection 
00AC  172  INT  R/W  0 = One set only 
1 =  2 sets keyboard selected 
2 =  2 sets with PV automatic 
switchover 
3 =  2 sets with setpoint (SP) 
automatic switchover 
Automatic 
Switchover 
Value (used with 
172 selection 2 
or 3) 
0038  056  FP  R/W  Within the PV Range in 
engineering units 
Local Setpoint 
Source (Number 
of LSPs) 
00AD  173  INT  R/W  0 = One Local Setpoint 
1 = Two Local Setpoints 
Power Up Mode 
Recall 
0082 130  INT R/W 
 Control Setpoint 
 Mode  Mode 
0 = MAN  LSP 
1 = AUTO  LSP 
2 = AUTO  Last RSP 
3 = LAST  Last SP 
4 = LAST  Last Local SP 
RSP Source  0083  131  INT  R/W  0 = None 
1 = Input 2 
Setpoint 
Tracking 
008A  138  INT  R/W  0 = None 
1 = LSP = PV (when in 
Manual) 
2 = LSP = RSP (when 
switched) 
Control Setpoint 
High Limit 
0007  007  FP  R/W  0 to 100% of PV 
(engineering units) 
Control Setpoint 
Low Limit 
0008  008  FP  R/W  0 to 100% of PV 
(engineering units) 
Control Output 
Direction 
0087  135  INT  R/W  0 =  Direct  
1 =  Reverse