Martel Electronics QM120ET - Manual (Page 2)

WIRE FUNCTIONS
0. Black 0V Negative power supply connection.
1. Brown RANGE Do not connect for 99999 Hour range.
Connect to 0V for 9999.9 Hour range.
Positive power supply connection.
3. Orange V-SENSE Connect to V+to start/continue counting elapsed hours.
Connect to 0V or do not connect to read TRIP or TOTAL value without counting elapsed hours.
4. Yellow PULSE Normally at 0V, this output goes High (+3.3V) every 100 hour interval in TRIP mode.
5. Green LZB Do not connect to display leading zeros.
Connect to 0V to blank all leading zeros.
When reading is 0000.0 or 00000, leading zeros are not blanked.
6. Blue RESET Connect momentarily to 0V to reset the display to zero (internally connected to V+ via pull-up resistor).
7. Violet TRIP/TOTAL Do not connect for TOTAL mode operation. In TOTAL mode, the elapsed hour meter cannot be reset to zero.
Connect to 0V for TRIP mode operation. In TRIP mode, the elapsed hour meter can be reset to zero.
2. Red V+
Specifications liable to change without prior warning QM 120 ET Issue 6 September/200. Applies to QM 120 ET
APPLICATIONS
Basic 3-wire operation:
- Leading Zeros are displayed
- Timing in TOTAL mode
Open S1 to read TOTAL value
without counting hours.
- 99999 Hour range
Red Orange
Black
0V
V+
-
Leading zeros blanked.
Close S1 to select TRIP mode.
Red Orange
Black
0V
V+
-
9999.9 Hour range
- Leading Zeros are displayed
- Timing in TRIP mode
Red
Brown Violet
Orange
Black
0V
V+
-
Using the PULSE O/P to drive an LED.
The LED will illuminate once after every hour.
Red
Brown Violet
Orange
Black
Yellow
Green Violet
S1
S1
R
LED
V+
-
0V
Hrs
TRIP TRIP
Hrs
Hrs
DISPLAY FUNCTIONS
8888.8 The 5 digit readout displays elapsed time in hours.
This symbol is displayed when trip mode is selected (see Wire Functions above)
The 10-segment incrementing bar indicates that the module is working correctly and counting hours.
This symbol is displayed when total mode is selected (see Wire Functions above)
- - - - - - - - - -
TRIP
TOTAL
Hrs
TOTAL TOTAL
Warning : Do not connect the following wires to V+: RANGE, PULSE, LZB, RESET, TRIP/TOTAL, as this may
damage the meter. The user must incorporate suitable protection circuitry in applications where
the voltage to any of the meter's wires can exceed 27V d.c., including transient conditions, else
damage to the meter may occur. In particular, for applications in harsh electrical environments,
e.g. automotive, suitable external protection must be provided to protect against "load dump"
conditions, transients, etc.
Martel Electronics, Corp. P.O. Box 770 Londonderry, NH 03053
Toll Free: (800) 821-0023 Phone: (603) 434-1433 Fax: (603) 434-1653