Description
The RAG128 is an intelligent remote analog-input and digital-I/O pod with an optically isolated RS-485 interface. Eight single-ended analog inputs provide 12-bit resolution, and each channel can be programmed for ±10 V, ±5 V, 0-10 V, or 0-5 V. The on-board microcontroller supports acquisition and local buffering independently of immediate host polling.
Serial Communications and Acquisition
An ASCII command/response protocol supports applications written in languages with serial and string functions. Up to 31 pods can share a two- or four-wire multidrop network, with each unit responding only when addressed by the host. Module addresses and baud rates are software programmable and retained in EEPROM. Low-attenuation twisted-pair wiring supports RS-485 runs up to 4,000 feet.
The converter supports 10,000 conversions per second in foreground mode and 6,670 conversions per second in background mode. Software commands or an on-board programmable timer initiate acquisition. Input data can be buffered locally for later retrieval.
Analog Expansion
AIM-16 multiplexers and signal conditioners extend the input system for additional channels, differential measurements, alternate voltage ranges, and low-level sensor signals. Each AIM-16 provides sixteen single-ended or differential channels with programmable gain. The pod provides the gain and channel-selection outputs used to control these expansion boards.
Digital I/O and Counter/Timers
The general-purpose digital interface has seven individually programmable input/output bits and one dedicated input. Open-collector outputs support application voltages up to 50 VDC and a maximum sink current of 350 mA per line, with a combined 650 mA limit. Eight additional TTL outputs provide multiplexer gain and channel control or general-purpose outputs when those functions are unused.
Three 16-bit counter/timers include one uncommitted counter and two cascaded counters used for timed A/D acquisition. The uncommitted counter exposes clock, gate, and output signals for application use and accepts clock inputs up to 10 MHz. A watchdog timer helps recover from processor and supply faults.
Installation and Power
The standard metal enclosure supports remote installation; a watertight, dustproof NEMA 4 enclosure is available. I/O connects through the 37-pin connector and on-card screw terminals. Separate local and isolated-interface supplies maintain serial isolation. The U-, WM-, E-, and S-prefix packages provide USB, wireless, Ethernet, and RS-232 host connectivity respectively.
Customized Analog I/O (MCOTS Options)
ACCES specializes in modified-COTS analog I/O. We can customize voltage ranges, sampling rates, filtering, isolation, gain stages, calibration profiles, firmware behavior, connector styles, and environmental ruggedness. If your analog requirements are unique, we excel at delivering tailored MCOTS analog hardware quickly and cost-effectively.
