8 channel A/D smart card
The Automation and Electronics, Inc. SDAM was designed to provide analog input expansion capability for Programmable Logic Controllers (PLCs). With a low power requirement and a wide operating temperature range, the SDAM 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 input module.
The SDAM is a microprocessor based 8 channel analog input board. The inputs can be used in either voltage or current sensing mode. Jumpers are used to configure each of the inputs. Connections are provided for end devices that provide their own loop power and also to provide the loop power to the end devices.
The analog inputs are digitized using a 12-bit analog to digital converter and put through a digital filter. The on-board option switches can be used to select the digital data filtering applied. The on-board microprocessor then makes these readings available to either 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 input 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 9" 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 100 mA @ 10 to 30 VDC |
| CPU / Memory | |
| CPU: | 68HC11 |
| Memory: | 128 kB flash, 32 kB EEPROM, 2 kB RAM |
| Input configuration | |
| Standard: | Eight analog inputs; 0-5 VDC or 0-20 mA selectable, 12-bit conversion, 130 mS. sampling interval, +/- 1.0 LSB linearity |
| Communications | |
| RS-485: | 9,600 baud; two RJ45 connectors |
| Protocols: | MODBUS RTU protocol |
