25
Installation and operation manual
–
DTHC-V4-2020
I/O
I/O error
Red
On:
Error on serial 1 or 2, SD card, cartridge, TM4 bus or TM3 bus.
SD
SD card access
Green
On:
SD card is being accessed
BAT
Battery
Red
On:
Battery needs to be replaced
Flashing:
Battery charge is low
SL1
Serial line 1
Green
Flashing:
Activity on serial line 1 to HMI touch screen panel
SL2
Not used
-
-
TM4
Not used
-
-
Expansion module TM3:
#3 Used PLC I/Os
Input
Description
I0
Blower Speed (RPM)
I5
Start/Stop Burner request (by others)
I6
Burner air proving switch (Alarm)
I7
Flue vent back pressure (Alarm)
I8
Burner On status proof relay
I9
Air Intake low pressure (Alarm)
I11
Valve proving system relay (with IRI option)
V0
24VDC input
Output
Description
Q4
Start/Stop Burner ignition command
Q5
Start/Stop Blower command
Q9
Alarm dry contact (by others)
TR0
Blower modulation (PWM)
Used expansion module I/Os
Port
Description
I0
Gas valve feedback (2-10Vdc)
I1
Burner modulation request (2-10Vdc) (by
others)
Q
Gas valve modulation (2-10Vdc)
