DAM-16DI
RS-485 interface, 16 digital inputs
Overview
- Industrial 16-channel digital input module.
- RS-485 interface and standard Modbus RTU protocol.
- Bidirectional opto-isolation on the input side; supports dry contacts and active wet contacts (NPN / PNP).
- Supports DI auto-upload on state change for event-driven and alarm use cases.
- Dual isolation on the communication path with fuse, TVS, and gas discharge tube protection.
- Stable and reliable for demanding industrial applications.
Specifications
| Item | Details |
|---|---|
| Power | 6–36 V DC |
| Interface | RS-485 |
| Baud rates | 4800, 9600, 19200, 38400, 57600, 115200, 128000, 256000 |
| Default format | 115200, N, 8, 1 |
| Digital inputs | 16 channels, 5–30 V; dry contact / active input (NPN or PNP) |
| Protocol | Standard Modbus RTU |
| LED | STA: solid on in Bootloader mode; slow blink when running; fast blink during communication |
| Dimensions | 121 × 72 × 34 mm |
Hardware interface
| Function | Pin | Description |
|---|---|---|
| Power DC 6–36 V | VCC | Positive |
| GND | Negative | |
| Unused | NC | Unused pin; leave floating |
| Communication | RS485 A+ | RS-485 A |
| RS485 B- | RS-485 B | |
| EARTH | RS-485 ground / earth | |
| Digital input | DI COM | Input signal common |
| DGND | Digital ground | |
| DI1–DI16 | Channels 1–16 digital inputs |
RS-485 bus wiring
Most PCs have no RS-485 port. Use a USB-to-RS485 adapter; connect A to the module A terminal and B to B. For multiple devices, use twisted-pair shielded cable in a daisy-chain topology.
Digital input wiring
DI1–DI16 are the 16 input channels; DGND is the signal ground. DI COM is the input common—it may be left floating, tied to supply positive, or tied to supply negative. Power may come from the module supply or an independent source.
- Floating: dry contact (passive) input
- Tied to supply +: low-level trigger, NPN wet / active input, 5–30 V DC
- Tied to supply −: high-level trigger, PNP wet / active input, 5–30 V DC
 Dry contact wiring |  NPN active (wet) input wiring |  PNP active (wet) input wiring |
Operation demo
Two tools are shown below. Either works for first bring-up; the web serial assistant is recommended for a quick start.
- Web serial assistant: no install; full frame display and parsing; less intuitive for register data.
- Modbus Poll: direct register access; easier to read input states; frames are not fully shown.
- Serial assistant
- Modbus Poll
- Open the serial debug tool, select the COM port, set 115200 N 8 1, and open the port.
- Enable hex display and hex send, set checksum to ModbusCRC16, send
01 02 00 00 00 10. The module should return the 16 input states.
- Use Module commands on the right to pick the module model and send preset commands, or expand entries to edit before sending.
- Common commands builds Modbus function-code frames from parameters.
- Install Modbus Poll and open it.
- Setup → Read/Write Definition: set Slave ID, Function
02 Read Discrete Inputs, Quantity to the actual channel count, Scan Rate 100 ms, then OK.
- Connection → Connect Setup: Serial Port, select COM port, 115200 N 8 1, OK.
- The window shows digital input states; changing an input updates the corresponding value.
- Display → Communication shows raw TX/RX data.
Resources
Documentation
- Modbus protocol overview
- Modbus specification (Chinese PDF)
- Modbus Application Protocol (English PDF)