4. SUPPLY VOLTAGE
The DRA-DCC-8 is powered by a DC power supply at a range of 15-32Vdc. In order to determine the minimum supply voltage, use the following equation:
Vmin = 8 + Rload(Ω ) * 0.02
where:
Vmin is the minimum required supply voltage.
Rload(Ω ) is the maximum output load including the leads resistance.
Note: If Vmin turns to be less than 15V, the minimum required voltage should be 15 Vdc.
5. MODES OF OPERATION
The DRA-DCC-8 unit can be operated in several modes, determined by an internal array of 8 DIP switches as follows:
4-20 or 0-20mA output current mode
Parallel control mode
Serial control mode
Self test mode
5.1 0-20 OR 4-20mA OUTPUT CURRENT MODE
Two current output spans are available: 4-20mA or 0-20mA selected by SW6. The DRA-DCC-8 receives 12 bits of data which determine the output current value. A channel data value of 4095 (FFF) is always interpreted as a 20mA output current. A channel data value of 0 (000) will produce a 0mA output current when SW6 is OFF, or 4mA when ON.
5.2 SWITCH SETTINGS
Parallel Control Mode
MODE | S1 | S2 | S3 | S4 | S5 | S6 | S7 |
0-20mA | OFF | OFF | X | X | X | OFF | OFF |
4-20mA | OFF | OFF | X | X | X | ON | OFF |