Omega LDP-146, LDP-126 POWER-UP and Operation, Excitation Voltage for Sensors, RUN Time Clock

8.5.- EXCITATION VOLTAGE FOR SENSORS

The unit supplies the Excitation Voltage for sensors, through control lines connector.

If the current required for the sensors installed is more than 100 mA then do not use this terminal. Install other external power supply. See paragraph 5 for technical specifications

9.- POWER-UP AND OPERATION

9.1.- REAL TIME CLOCK

At power-up, the unit displays the message MAStEr for 6 decade version or MASt for 4 decade version and will start to operate.

If a failure occurs then will display the messages CHIP or SET. The message CHIP means that the failure is the internal hardware and the message SET means that the data stored in the memory is damaged and it must be restored.

The restore data operation can be made while the instrument is in normal operation or while the error message SET is on the display using the control lines HOURS, MINUTES & SEC-

Terminal		Function
14	Hours	Increment hours
6	Minutes	Increment minutes
13	Seconds	Reset seconds

ONDS.

Reaction to the control lines is once per second.

To obtain a complete reset in a real time clock configuration, connect terminals 14 & 13 to GND simultaneously. The display can be switched in to Run Time Clock mode by inputting an active signal on to any of the three control lines START, STOP or RESET.

9.2.- RUN TIME CLOCK

At power-up, the unit displays the message MAStEr for 6 decade version or MASt for 4 decade version and will start to operate.

If a failure occurs then will display the messages CHIP	An active signal		Function
or SET. The message CHIP means that the failure is the
	applied to pin :
internal hardware and the message SET means that the
alarm value stored in the memory is damaged and it	11	Reset	Resets/Preset the timer
must be restored.
	3	Start	Starts the timer
Use the control lines RESET, START & STOP to control
	10	Stop	Stops the timer running
the timer. Once the unit is displaying the run time clock
			Starts the timer if not running
the three control lines operate as show in the table.

An active signal can be either active high or active low

depending upon the internal configuration of the unit as shown in paragraph 10.2.4.

The factory default settings are for contact closures to GND for all three inputs. Reaction to the control lines is once per second.

Note on the 4 decade clock the run time clock may be either for hours and minutes or for minutes and seconds. During run time hours and minutes, the colon will flash on and off every second while the clock is running to indicate the clock is running.

9.2.1.- UP / DOWN TIMING

The run time clock has two basic modes of operation; a run up clock or a run down clock. These modes are controlled by a internal DIP switch (See DIP SWITCH CONFIGURATION in paragraph 10.2.3).

Run up clock

Reset will clear the clock to zero. When the alarm point is reached, if the alarm is enabled, the clock will stop and the whole display will flash and the alarm output will be activated, until the clock is reset. If the alarm is disabled, the clock will run up to 99 minutes 59 seconds (or 99 hours 59 minutes) and then roll over zero.

Run down clock

Reset will preset the clock to the alarm point. When zero is reached, if the alarm is enabled, the clock will stop and the whole display will flash and the alarm output will be activated, until the clock is reset. If the alarm is disabled, the clock will run down to zero and then underflow to 99 : 59.

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