AW Gear Meters EMO-3000 - Manual (Page 9)

EMO‐3000
Operation and Programming Manual
8
 4‐20 mA or 0‐5 V output
 Power supply: 110/220 Volts AC, 50/60 Hz
DM‐3000 Hardware
In most cases, install the DM‐3000 using the 9‐Pin D‐Sub power/communication cable shipped with the
unit. Standard cable length is 15 feet; maximum length is 50 feet. Longer lengths, though not
recommended, can be accommodated. The environment through which you lay the cable determines
interference level. Avoid electric motors, servos and other noise sources to maximize communication
performance. See Appendix E for details about the cable.
The serial communication cable, which connects the EMO 3000 to the DM 3000, carries 15 VDC power.
There is danger of damage if the 15 volts DC on Pin 1 is connected to a host computer or PLC. Only use
the cable for its intended use.
Power Supply
The cable from the EMO‐3000 normally powers the DM‐3000. To power the unit separately, hook up a
12VDC power pack or 12‐15VDC power supply to the power jack connector.
Once powered separately, the DM‐3000 still requires a communication cable with the pin layout shown
in Appendix E, but the 15 VDC on Pin 1 is no longer required.
If you use both the power jack and the cable at the same time, the DM‐3000 will function normally.
EMO‐3000 Card Hardware Description
Each EMO‐3000 channel card is an independent fluid monitor/control computer. The system is based on
the V25 microprocessor and utilizes a 256 Kbyte EPROM (electronically programmable memory), and
eight Kbyte RAM (random access memory). All communication is via RS‐232C to the bus board, but the
EMO‐3000 channel card rack has both RS‐232 and a 4‐wire RS‐422 type communication to PC or PLC.
After July, 1993, the protocols are RS‐232 and 4‐wire RS‐485. The RS‐485 protocol is backward
compatible with the RS‐422 protocol. Also, optical insulated serial ports are available upon request (not
to the DM‐3000).
The Input/Output pins and the frequency inputs are isolated with an opto‐coupler and a 4‐position
frequency divider for the A input, and an OP‐Amp circuit in which the sensitivity can be set for 50mV,
1.75V, or 3.7V input for the B input. There is a 12‐bit D/A converter and a high‐speed multiplexing chip
for the analog Input/Output control. All of the Analog control circuits employ high impedance buffer OP‐
Amps and diode protection to the microprocessor. The cards mount to the bus board using a 64‐pin
male connector. The 15‐pin connector is for the Limit I/O pins, the Analog I/O pins, the reset, and
frequency inputs as well as a 15 Volt 25 mAmp power supply connection. Refer to Appendixes Q and R.
Warning!