35 digital outputs module - MIDAM BDO3501
Microprocessor controlled module featuring 35 binary ( digital ) outputs. The serial line communication is based on Modbus RTU ( RS485 ) protocol. Native modbus map grants seamless integration into variety of PLC/SCADA systems.
- Microprocessor-controlled module
- Modbus RTU (RS485)
- Native Modbus map
- Integration into PLC / SCADA systems
Function
The BDO3501 module controls up to 35 digital (open collector) outputs. The outputs are designed for switching small voltage up to 30 V DC, maximum current 0,5 A. It is recommended to use small DC relays connected to the outputs in order to galvanically separate power part from low voltage circuits. The device has factory-set values to ensure the correct default function and allows direct reading and writing of values to the Modbus map, which is available in a separate document. All settings are also stored in the Modbus map directly in the device. If the module is terminating the communication bus, i.e. it is the last in line, a terminating 120 R resistor may be switched on by short-circuiting of the BUS END DIP switch. Three LEDs located inside of the housing enable fast diagnostics – power, communication and system circle indication. The communication circuits are protected against overvoltage and galvanically isolated from other parts of the module. 35 LEDs indicate the status of each of the output separately. The module is equipped with a watchdog.
Application
- Module with 35 digital outputs
- Binary signal control
- Integration into PLC topology
- General-purpose use
Addressing
The Modbus address can be set in two ways. Using DIP switches, they increase their bit weight from right to left, see image with example where address of 98 is set by activation of switches 2, 3, and 7 with bit weight of 64, 32, and 2 respectively. Valid settable range is 1 to 254. Address 0 (all switches OFF) means that the address is set as entered in the Modbus table. Address 255 (all switches ON) brings the module to INIT (factory settings) mode, where Modbus address is 1 and communication parameters are set to 9600/ 8/N/1. Software addressing is available using appropriate software tool delivered by the device manufacturer. The software addressing feature is active provided the hardware addressing switch is set to 0 only. All changes apply after the module is switched off and on again.
Configuration
The device is configured using the manufacturer’s tool or with a standard modbus tool, modifying the appropriate registers. The different operation modes and user access can be configured in this way. Modifications to the controller configuration can be made afterwards without the need for any special tools.
PLC system integration
The module can be integrated via the Modbus RTU (RS485).