ADLINK NuDAM-65xx Communication Module Networking and Configuration Guide

This module allows different baud rates to be set on the RS-232 and RS-485 sides (set separately through configuration commands), greatly enhancing the ability to bridge devices with different speeds.

Network construction and initialization process

1. New module initialization (address and baud rate settings)

All newly purchased NuDAM modules (excluding ND-6521, but including I/O modules) have factory default address 01, baud rate 9600, and verification disabled. To avoid address conflicts, each module must be assigned a unique ID. The initialization steps are as follows:

Enter default state: Short circuit the DEFAULT * pin of the module to ground and then power it on. At this time, the module temporarily uses address 00, baud rate 9600, and verification disabled.

Connect hardware: Use ND-6520 (or ND-6530) to convert the host RS-232 to RS-485, ensuring that the converter baud rate is set to 9600. Connect the DATA+(Y), DATA - (G),+Vs (10-30V), and GND of the module.

Send configuration command: Format is% (OldAddr) (NewAddr) 40 (BaudRate) (ChecksumFlag)<CR>. For example, changing the address from 01 to 30, keeping the baud rate at 9600, and disabling the checksum:% 0130400600<CR>. Among them, 40 is the type code of the digital I/O module (ND-6521 also uses 40), 06 corresponds to 9600, and 00 indicates that verification is disabled.

Verification response: Received! 30<CR>indicates success. Remove the DEFAULT * short circuit, power on again, and the module will run according to the new configuration.

2. Add the new module to the existing network

After configuring the address, baud rate, and checksum of the new module, it needs to be consistent with the network. Operation sequence: Turn off the host and network power; Connect the DATA+, DATA -, and power cords of the new module to the bus in parallel; Confirm the polarity is correct; After powering on, use the management software to scan the entire network and verify if the new module is correctly identified.

3. Special configuration of ND-6521

The configuration command for ND-6521 is more complex, with a Data Flag of 4 characters (WXYZ) used to set address mode, checksum, interface type, RS-232 data format, etc. For example,% 013040662103<CR>means changing address 01 to 30, RS-485 and RS-232 baud rates are both 9600 (two 6s), W=2 (address mode+RS-485+no checksum), X=1 (additional CR), Z=03 (8 data bits, no checksum, 1 stop bit). For specific location definitions, please refer to section 5.4.3 of the manual.

Specification for Terminal Resistance and Shielding Grounding

Terminal resistor: Connect a 120 Ω resistor in parallel at both ends of each physical bus. On the wiring terminals of ND-6520 or ND-6510, DATA+and DATA - can be directly bridged. If a branch line is used, it should be connected at the shortest point of the branch line or an active terminal should be used.

Shielding layer: The shielding layer of the shielded twisted pair cable should be connected to the equipment casing ground (FGND) and grounded at a single point on the host side. If the on-site interference is severe, the shielding layer can be connected to the protective ground at regular intervals, but it is necessary to avoid forming a ground loop.

Key points of command system and communication protocol

All modules of NuDAM use a unified ASCII command/response protocol, with the command format being:

(LeadingCode)(Addr)(Command)[Data][Checksum]<CR>

Guidebook: such as $(read configuration), # (output),% (write configuration),~(watchdog),&(ND-6521 specific), etc.

Address: Two hexadecimal digits (00~FF).

Checksum: Optional. When enabled, the sum of all ASCII characters must be calculated and the lower byte must be taken, represented in two hexadecimal digits. For example, in the command $012B7<CR>, B7 is the checksum.

Response: Valid command returned! Or>at the beginning, invalid return?.

For ND-6521, in addition to the basic configuration, it also provides data transparency function: after setting the delimiter (such as {), use {30Data<CR>to directly send data to the RS-232 device at address 30. In addition, the host watchdog command (~* *<CR>) can uniformly reset the watchdog timers of all modules to prevent output locking after the host crashes.

Software Tools and Daily Maintenance

ADLINK provides the "NuDAM Administration" software, which runs on the Windows environment. Its main functions:

Search network: Scan the address range (00~FF) and list all online modules and models.

Terminal simulation: Directly send any command, observe the response, and facilitate debugging.

Configuration and monitoring: graphically set addresses, baud rates, I/O modes, etc.

Batch command: executable script file (BATCH.CMD) for automated testing.

In daily maintenance, regularly check whether the wiring terminals are loose and observe the status of the module LED: a green light that is constantly on indicates normal reception, flashing indicates data transmission, and turning off the light indicates no power supply. If communication is abnormal, first confirm the power supply voltage (10-30V), then use terminal software to send $002 to address 00 (assuming the module is in default state). If configuration information is returned, it proves that the physical layer is good.