Table of Contents

ezeio MkII I/O Expander

Description

This device is designed by eze System to provide additional input and output capacity to the MkII ezeio. Each I/O Expander adds 8 discrete inputs, 8 digital outputs and 2 analog outputs. Multiple I/O Expanders can be connected to one ezeio MkII controller. Two versions of the MkII I/O are currently available EM2088 (eze-CAN only) and EM2088-MB which provides the option of connecting via Modbus RTU. Docking to the ezeio's EXP port (eze-CAN) allows the expanders I/O's to function as if they were onboard resources of the ezeio, including the use of ezeio drivers (discrete input, pulse input, thermistor, and digital output) for configuration. Utilizing the Modbus RTU port allows the I/O Expander/s to be located remotely (up to 1000 meter of hard wired serial bus length). For the Modbus RTU option a dedicated driver is used to configure the 8 inputs.

Do not connect both serial buses. Only one form of serial bus communication can be used to connect to the ezeio controller.

eze-CAN Modbus RTU
Bus length Docks directly 1000 meters
Sample speed 100 ms Varies base on # & performance of MB slaves
Driver options Same as ezeio controller 8I8O Expansion Module
Power Supplied thru ezeio controller EXP port Barrel jack or Modbus port

Model information

Part number Model System connectivity For use with
EM2088 ezeio I/O Expander eze CAN ezeio controller only
EM2088-MB ezeio I/O Expander + MB eze CAN / Modbus RTU ezeio controller or 3rd party Modbus RTU master

Local connectivity includes;

Quantity Description Comment
Discrete inputs 8 Individually configurable for 0-10V, 0-30mA, Resistor, Thermistor, Pulse
Discrete outputs 8 2 digital (voltage output) Outputs supply voltage
Analog outputs 2 0-10VDC (voltage output) Recommend greater than 12V supply to insure full 0-10 range
Modbus/RTU 1 Serial (RS485) port supporting the Modbus/RTU protocol Only operates as slave device
EXP port 2 eze CAN Expansion ports for docking to ezeio and Expanders Only operates as client of ezeio

Discrete inputs

There are eight (8) discrete inputs on the ezeio. Each input can be individually configured to monitor voltage, current, resistance or pulses. The configuration is done via the web interface at https://eze.io.

More information about connecting to the inputs is available here.

Discrete outputs

There are 10 outputs on the I/O Expander. The function of each output is completely controlled by software.

Output 1 thru 8 are purely on/off. They will output the supply voltage when on, and no voltage when off.

Analog (Output) 1 & 2, output an analog voltage variable between 0 and 10V. The software controls this in 100mV steps (0-100%).

More information about connecting to the outputs is available here.

Functional overview

As described above, the I/O Expander provides the ezeio with additional input and output capacity. The two options for communicating with the ezeio require different installation and set-up processes. There are also performance difference between the two modes of operation. Below are complete instructions and operation details for connecting via the eze CAN EXP port followed by those for connection via Modbus RTU.

Connect via EXP port

Features & Benefits


Physical installation

Changing device ID/address

Default address is 1, unless otherwise noted


Adding Inputs and Outputs to eze.io configuration

Use any of the drivers listed below to add inputs and outputs to the ezeio controllers configuration

Connect via Modbus RTU

In this communication mode the I/O Expander functions like a 3rd party device. Since Modbus RTU is an open protocol, it could be sold separately and use with almost any Modbus master.

One of the effects of using this communication mode is a slower register update rate. Modbus RTU operates at a much slower speed than CANbus/eze-CAN. Update rates will vary based on the number of devices and registers polled. Update rate could range from several times per second to a slow as once per minute, with high traffic and/or comm issues.

More information about Modbus/RTU is available here.

Features & Benefits


Physical installation

Changing device ID/address

Default address is 1, unless otherwise noted


Changing data bit rate (baud rate)

Default address is 19,200, unless otherwise noted

Register Value = Baud rate

  1. = 2,400
  2. = 4,800
  3. = 9,600
  4. = 19,200
  5. = 38,400
  6. = 57,600
  7. = 115,200