RDI-54 Remote 54-Channel Digital Input Pod
54 remote digital inputs with isolated RS-485 and change-of-state detection
Features
- 54 digital inputs for remote monitoring
- Opto-isolated RS-485 serial interface
- Digital input voltages up to 50 VDC
- Byte-by-byte sequential or random-access input scans
- Per-input change-of-state detection and 8-bit software event counters
- Software-programmable address retained in EEPROM
- NEMA 4 enclosure and on-board watchdog
- Designed and manufactured in the USA
$325.00
In StockDescription
RDI-54 provides 54 digital inputs for remote monitoring through an opto-isolated RS-485 connection. It is housed in a NEMA 4 enclosure for use in harsh atmospheric or marine environments and accepts digital input signals up to 50 VDC.
The input lines are latched into seven 8-bit registers. Software can scan the registers sequentially or select them individually, one byte at a time. Change-of-state detection is enabled independently for each input, making the pod useful for monitoring contact closures and openings. Input software counters are also provided.
The serial interface supports addressed multidrop operation with a software-programmable pod address from 00h to FFh. The address is stored in EEPROM and restored at power-on. Standard half-duplex operation requires no switch or jumper settings; optional jumpers bypass the opto-isolators.
Communication supports software-selectable rates from 1,200 to 57,600 baud. An on-board watchdog resets the pod if the microcontroller stops responding or the supply drops below 4.75 VDC. Data stored in local RAM can be retrieved later through the serial interface.
The base model uses RS-485. Packaged USB, wireless, Ethernet, and RS-232 versions provide additional host-connection choices.
Modified-COTS (MCOTS) Customization
ACCES can tailor any standard product to your precise requirements — electrical, mechanical, firmware, environmental, or connector-level. Common MCOTS options include alternate I/O ranges, isolation enhancements, firmware changes, private labeling, conformal coating, extended temperature operation, ruggedized enclosures, and military-grade components. If this product is close but not a perfect fit, our engineering team can deliver a rapid-turn MCOTS variant with minimal NRE and dependable, Made-in-USA quality.
Digital Inputs
| Channels | 54 inputs, latched into seven 8-bit registers |
|---|---|
| Scanning | Sequential or random access under software command, one byte at a time |
| Event counters | 8-bit digital-input software counters |
| Change-of-state detection | Individually enabled input flags, readable through the serial port |
| Logic low | −0.5 to +0.8 VDC |
| Logic high | +2.0 to +50.0 VDC |
| Low-level input current | 450 µA maximum |
Serial Communications
| Interface | Opto-isolated RS-485; up to 32 drivers and receivers on the line |
|---|---|
| Pod address | Software programmable from 00h to FFh (0–255); stored in EEPROM |
| Input common-mode voltage | 300 V minimum with optical isolation; −7 to +12 V with opto-isolators bypassed |
| Receiver sensitivity | ±200 mV differential |
| Receiver input impedance | 12 kΩ minimum |
| Transmitter drive | 60 mA; 100 mA short-circuit capability |
| Programmable data rates | 1,200, 2,400, 4,800, 9,600, 14,400, 19,200, 28,800, and 57,600 baud |
Processing, Power and Environmental
| Processor and memory | 8031 microcontroller; 8K RAM and 8K EEPROM, with 32K × 8 EEPROM option |
|---|---|
| Watchdog | Processor watchdog and reset below a 4.75 VDC supply level |
| Serial-interface power | 7.5 to 25 VDC at 40 mA for the opto-isolated section |
| Local power | 7.5 to 16 VDC at 100 mA typical |
| Operating temperature | 0 to 65 °C; optional −40 to +80 °C configuration |
| Temperature derating | Maximum operating temperature depends on the applied power-supply voltage |
| Storage temperature | −50 to +120 °C |
| Humidity | 5% to 95% RH, non-condensing |
| Enclosure | NEMA 4 enclosure |
| Enclosure dimensions | 4.53 × 3.54 × 2.17 in. (approximately 115 × 90 × 55 mm) |
Select the standard RS-485 model or a packaged host-connectivity version. The USB, RS-232, Ethernet, and wireless versions use connectivity hardware with the remote pod. Contact ACCES for configuration, pricing, and availability of packaged versions.
Call for Pricing
- U-RDI-54 — 54-channel remote digital input pod, USB host-connection package
- WM-RDI-54 — 54-channel remote digital input pod, Wireless host-connection package
- E-RDI-54 — 54-channel remote digital input pod, Ethernet host-connection package
- S-RDI-54 — 54-channel remote digital input pod, RS-232 host-connection package
| Model | Description | Price (USD) | |
|---|---|---|---|
| RDI-54 | 54-channel remote digital input pod, RS-485 | $325.00 | |
| U-RDI-54 | 54-channel remote digital input pod, USB host-connection package | Call for price | |
| WM-RDI-54 | 54-channel remote digital input pod, Wireless host-connection package | Call for price | |
| E-RDI-54 | 54-channel remote digital input pod, Ethernet host-connection package | Call for price | |
| S-RDI-54 | 54-channel remote digital input pod, RS-232 host-connection package | Call for price |