2 channel D/A smart card
The Automation and Electronics, Inc. SDAO was designed to provide analog output expansion capability for Programmable Logic Controllers (PLCs). With a low power requirement and a wide operating temperature range, the SDAO is ideal for use in remote 120 VAC, 24 VDC, or solar powered distributed I/O systems. It can also be used as a stand-alone MODBUS analog output module.
The SDAO is a microprocessor based 2 channel 4-20 mA analog output board. The outputs can be used in remote or local power mode. In remote power mode, the 4-20 mA loop power is provided externally. In local power mode, the SDAO provides the 24 VDC loop power. On-board jumpers configure the output types. The on-board microprocessor controls the analog outputs on this board from communicated values from host systems or master controllers via a serial data highway.
The data highway is implemented using the built in RS-485 serial port. All of the Smart Card series can be daisy chained together using these serial ports. Each Smart Card responds to MODBUS polls or commands from a master. An on-board address selector switch allows each board to be easily configured for any MODBUS address. This RS-485 data highway can then be used to create a scalable, flexible input / output expansion array.
Features
- Analog output value backup (24 hour via on-board capacitor)
- MODBUS RTU protocol
- On-board address switch (0-255)
- Four on-board option switches
- Two RJ45 jacks for RS-485 serial data
- Selectable RS-485 termination
- Expansion connector for our P-type piggyback modules
Specifications
| Mechanical | |
|---|---|
| Size: | 4-1/2" x 6-3/8" PC board |
| Mounting: | Snap track |
| Environmental | |
| Operating temperature: | -40 to +158 deg. F (-40 to +70 deg. C) |
| Relative humidity: | 5 to 90% non-condensing |
| Power requirements | |
| Typical: | Processor - Less than 50 mA @ 10 to 30 VDC |
| CPU / Memory | |
| CPU: | 68HC11 |
| Memory: | 128 kB flash, 32 kB EEPROM, 2 kB RAM |
| Output configuration | |
| Standard: | Two analog outputs; 0-20 mA or 4-20 mA 16 bit conversion; 0.15% maximum error; RLoad 100 Ohm min; ((VL-3)/.02) max |
| Loop power: | 12 to 30 VDC |
| Communications | |
| RS-485: | 9,600 baud; two RJ45 connectors |
| Protocols: | MODBUS RTU protocol |
