FEATURES

• ASCII RS232 Interface (optional)
• Analog output, 4-20mA or 0 to ± 10 VDC (optional)
• Optional TRMS AC Input
• High/Low limit set points
• 4 l/2 digits of display and control
• Input and power via screw terminals
• Easily scaled for reading out directly in engineering units
• Heavy duty form C relay closure for each limit
• Optional dead zero (LSD) for 5 1/2 digit display
• Optional three state parallel BCD outputs with single line enable
• High input impedance (109 ohms, DC input only)

Series 240/250C
A dual or single set point comparator and voltmeter in the same package, and easily scaled input are just a few of the features that make this voltmeter/controller unique in the field of panel instrumentation. No wiring between two units is required, just apply power, input a voltage, dial in the set points, and the unit will indicate if the voltage is above, between, or below the set points. Scaling is accomplished by simply picking the desired voltage off a thick film resistor network by making a few solderless jumpers internally. For a nominal charge DCI will scale the Series 240C/250C to read almost anything desired. Just specify input voltage and full scale reading desired when placing order. It will be set up prior to shipment. For instance if a transducer has an output of 0-5VDC, which represents 0-1750.0 pounds, DCI will program the reference and calibrate the meter to your needs.

Systems outputs include latchable three state TTL compatible parallel BCD outputs and RS232 serial interface. The three state outputs allow the output lines to be wired in parallel with other outputs and then called up using the single line enable thereby reducing required wiring. The hold/convert line allows single conversion capability greatly enhancing systems uses.

Input protection:
10⁹ ohms up to ± 5 VDC input voltage. Above 5VDC, 5megohms minimum.

Input bias current:
50pA typically.

Input voltage range:
0 to ± 20 volts, 0 to ± 200 mV on standard models, or up to 750 volts using factory installed scaling resistors. (See option -06)

NMRR:
70db;

CMRR:
70db.

Rollover error:
30 microvolts typically; 100 microvolts maximum.

Front panel controls: Thumbwheel switches 4 l/2 digits, 0-9 and optional polarity selector for each limit.

Visual indicators: 4 1/2 digits. .56" LED's ± 1.9.9.9.9

Decimal points programmable on rear I/O connector.

Red LED dots for "LO" and "HI", both dots out during "IN" condition.

Inputs:
External convert/hold: Requires logic zero to hold. For single conversion, hold must be allowed to go high for a minimum of 10 milliseconds and a maximum of 100 milliseconds. For continuous run operation hold line must be left open or high. Input loading 1 LPTTL load.

Three state input: (01option only) Requires logic level zero. Forces BCD outputs to a high impedance state for bussing applications. Input loading 1LPTTL load. Pulled up internally with 20Kohm resistor.

Latch input: (01 option only) Requires logic zero. Latches BCD data without affecting display. Data will be held as long as latch is held low. Input loading 1 LPTTL load. Pulled up internally with 20Kohm resistor.

Outputs:
ASCII RS232 compatible (optional); format: 1 start bit, 8 data bits, 1 stop bit, and no parity bits.

BCD outputs (optional); latchable 3 state + 8421 TTL logic level for each digit plus overrange and polarity. Will drive 4 TTL loads.

4-20mA output (optional); maximum load 500 ohms. Offset and span programmable via solderless jumpers and potentiometers.

Analog output (optional): 1mV per digit into 10K ohm (maximum 10 volts).

5 Volt logic level output for "LO", "IN", and "HI", will drive three TTL loads.

Form C relay closure for each limit. Contact ratings 6 amps @ 28VDC or 2.5 amps @ 115VAC resistive or 1 amp @ 230VAC resistive.

Conversion rate:
Three per second standard, optional seven and one-half per second.

Power:
115VAC 50-400 Hz, 8 watts maximum
230VAC 50-400 Hz, 8 watts maximum (optional)
10-30VDC 500 mA max. (optional)
5VDC 600 mA max. (optional)

Input Current:
100nA typically, 300nA maximum

Operating temperature:
-20° to +60° Celsius.

REAR PANEL CONNECTORS PIN OUT AND DESCRIPTION
TB1
W Analog input (LO)
X Analog input (HI)
Y Power supply input (Power in on DC models)
Z Power supply input (Power return on DC models)

J1