Digital input module romod 16DI

RS-485Modbus RTU16 digital inputs

Product information
The romod 16DI digital input module provides monitoring of up to 16 digital signals for industrial control applications. Typical uses include signalling of operating states and fault conditions (e.g. frost, filter dirty, fan belt fault) and reporting discrete status positions such as damper positions. Inputs are switched with 24 V by external dry contacts connected to the module terminals. The COM terminals define the reference potential and can be set to 0 V or 24 V; COMs are internally connected but not tied to power supply GND, so a reference potential must be provided.

Technical data
Modbus register settings allow each input to be configured for normally-open or normally-closed operation. Each of the 16 status LEDs has a configurable color (red, green or orange) via a Modbus configuration register; LEDs can also be controlled individually via Modbus commands if enabled in the configuration register. Inputs support counting of DC pulse signals (counters are not retentive on power loss). A prescaler can be set per input to count e.g. every 2nd or 3rd pulse; changing the prescaler adjusts corresponding counter values retroactively. Minimum pulse duration for reliable detection is 10 ms. A change register indicates which DI(s) changed since the last read; reading this register resets all bits to zero, while multiple rapid changes are still signalled.

Technical specifications

• Type: Digital input module with 16 digital inputs (DI)
• LEDs: 16 status LEDs, color configurable per LED (red / green / orange) via Modbus
• LED control: Individual LED control via Modbus commands (if enabled by configuration register)
• Input control: 24 V switched by external dry contacts; COM terminals selectable as 0 V or 24 V reference (COMs internally connected)
• Input mode: Each input configurable as normally-open or normally-closed via Modbus register
• Counter functionality: Inputs usable as pulse counters for DC signals; prescaler adjustable per input; counters not retentive
• Pulse detectability: Minimum pulse duration 10 ms
• Change register: Register available that reports which DI(s) changed since last read; reading resets the register
• Bus: RS485, Modbus RTU; autobauding supported
• Supported baud rates: 9,600; 19,200; 38,400; 57,600 Baud (Autobauding)
• Bus cycle time: Depends on baud rate and number of addressed data points
• Memory: Internal microcontroller; configuration stored in internal EEPROM (up to ~100,000 write cycles)
• Max. counter value: 4,294,967,296; counter values not stored on power loss
• Power supply: 24 V AC/DC via terminals; current consumption max. 150 mA (DC) / 220 mA (AC), all DIs loaded
• Power dissipation: Max. 3.6 W (DC) / 5.3 W (AC), all DIs loaded
• Environmental: Operating 0...50°C; transport/storage 0...70°C; relative humidity 10...90% non-condensing
• Protection class: IP20
• Mounting: DIN-rail