S7999B SYSTEM DISPLAY
67
65-0283—2
Setpoints:
Modulation (0-500°F or 0-750 psi)
On-Off (0-500°F or 0-750 psi)
Low Fire Hold (0-500°F or 0-750 psi)
APPLICATION NOTE
Application:
Water Temperature Load Control
Description:
On-off and modulating outputs to start/stop and adjust firing rate to maintain a control
setpoint.
M24241
LOW FIRE
HOLD CONTROL
CIRCUIT
FIRING RATE
MOTOR
INTERFACE
MODBUS COMMUNICATION
HONEYWELL S7810M
L1
ON–OFF CONTROL
BURNER CONTROL
L1
D+
+
-
+
-
R
D-
SHIELD
26
27
25
21
19
17 18
16
5
9
8
6
L2
L1
G
C
A
B
L1
L2
RTD SENSOR
100 OHM
UDC
CONTROLLER
Digital Inputs:
None
Digital Outputs:
On-Off relay
Optional: Modulation Alarm1 (ON
when at or below Modulation setpoint,
OFF when above Modulation setpoint)
Optional: Low Fire Hold Alarm2 (ON
when at or below Low Fire Hold
setpoint, OFF when above Low Fire
Hold setpoint)
Analog Inputs:
Vessel water sensor
temperature (0-500°F) (100
Ω
RTD)
Analog Outputs:
PID modulation (4-20mA) to control
firing rate. Modulation based on
modulation setpoint.
Application File:
temp01.nge
temp02.nge
temp03.nge
temp04.nge
Range
0–300°F
0–300°F
LOW FIRE HOLD
0–500°F
0–500°F
LOW FIRE HOLD
Controller
Model (see
footnote)
1
2
1
2
Algorithm:
CTRALG
PIDA
PIDA
PIDA
PIDA
TIMER
DIS
DIS
DIS
DIS
Output:
OUTALG
CURRENT
CURRENT
CURRENT
CURRENT
Input 1:
IN1TYP
100H
100H
100H
100H
IN1 HI
1200
1200
1200
1200
IN1 LO
-300
-300
-300
-300
Input 2:
IN2TYP
DIS
DIS
DIS
DIS