Created date: June 25th, 2020

Introduction

In the picture below you can see an overview of the I/O terminal blocks of an e-Series controller:

• Configurable inputs (CI0 to CI7) and configurable outputs (CO0 to CO7) can be used as general purpose I/O or safety I/O
• Digital inputs (DI0 to DI7) and digital outputs (DO0 to DO7) can be used as general purpose digital I/O
• Analog inputs (AI0 to AI1) and analog outputs (AO0 to AO1) can be used as general purpose analog I/O
• Additional digital inputs (DI8 to DI11) can be used as encoder digital inputs (for conveyor tracking)

There are 8 dedicated digital inputs which can be extended to a total number of 18 by utilizing the 8 configurable inputs, and the 2 digital inputs of the tool flange (TI0, TI1). The dedicated digital outputs have the same amount of 8, with the possibility to expand with 8 configurable and additional 2 outputs at the tool flange (TO0, TO1).

The I/O are powered by the internal 24V power supply. If the internal supply is not sufficient, it is possible to connect an external power supply (see e-Series user manual chapter 5.4.1 Common specifications for all digital I/O). The I/O in the control unit can be used to connect a variety of components, such as pneumatic relays, PLC, sensors, buttons and lamps.

If you need additional digital I/O, this can be set up with an external Modbus I/O extender block.

How do I connect a push button and an indicator lamp?

When installing a push button that for instance could be used to start the program, connect the button as shown in the picture. Mount a wire in the +24V terminal in the digital input block, connect it to the contact element in the push button. Connect a wire to the other side of the contact element going back to the DI0 terminal.

The only thing missing now is to assign the start program action in the I/O Setup Menu (see picture below). Select the digital input (DI0) and assign the action “Start program” to it. The robot should be in remote control for this function to work (see e-Series user manual chapter 5.4.7 Remote ON/OFF control). To learn more about assigning functions to I/O we have a dedicated article on the subject: Assigning special functions to inputs and outputs.

To install an indicator light that shows the robot is in operation you need a 24VDC lamp. On the picture above you can see how the 0V terminal of the digital outputs is connected to minus (0V) on the lamp and DO4 is connected to plus (+24VDC).

In the I/O Setup tab that is shown in the picture it has been named “robot_active” and been given the action “High when running-low when stopped”. This means when the robot is in operation there will be +24V on the digital output and the light will be on.

How can the controller be protected from noise interference?

If you have a suspected component that could create noise interference in your application, it is beneficial to try and mitigate the interference. This can be done by creating a galvanic isolation.

The picture below shows one way of doing that. The relay is controlled by the digital output DO4 and the signal in this case to a frequency converter is taken directly from an external power supply and controlled with a NO contact element in the K1 relay.

The same principle can be used in case you have components that need a different type of signal, for instance 230VAC or components that consume more than a total of 2A which is the max consumption for the I/O connections, using the internal power supply.

Note that there is an option to connect an external power supply to the robot controller and deliver a total of 6A for the I/O (see e-Series user manual common specifications for all digital I/O).

Where can I connect an encoder with digital pulses?

You can use the dedicated horizontal digital input block DI8-DI11 to connect a total of two encoders, they are placed on the left-hand side on the overview picture above. The inputs are only visible in the menu: Go to: Installation → General → Conveyor Tracking.

How are the configurable I/O switched from safety to general purpose?

As shown in the first picture, go to: Installation → Safety → I/O and set the function assignment to “Unassigned”. You will now be able to use the configurable I/O as general purpose I/O. For example, you can assign one of the build-in actions in the I/O setup menu.

If you decide to use the configurable I/O as safety I/O, there is a variety of functions which can be chosen in the drop-down menu. Note that only 4 inputs and 4 outputs are available. Each safety I/O must be wired in dual channel, for redundancy purposes. This means that 1 safety input will use 4 terminals.

More information on the configurable I/O can be found in the e-Series user manual chapter 5.4.2 Safety I/O.

How can I use the analog inputs and outputs?

There are 4 analog inputs and 2 analog outputs available, 2 of the inputs are located at the tool flange. Analog inputs are often used to receive a variable signal, this could for instance be a pressure transducer which returns a signal from 4-20mA in the scale of 0 to 100 bar. It is preferable to use the current signal [mA], since it is less sensitive to interferences. There is also an option to receive and send a voltage signal in the range of 0-10V.

With the build in analog outputs there is an option to send a signal from 4-20mA or 0-10V to a chosen receiver. This could for instance be utilized to control a conveyor belt with an analog speed control input.

The examples show how to connect an analog sensor to the analog input (AI1) and a conveyor belt with analog speed control input to the analog output (AO0).

How can the settings be interchanged between current [mA] and voltage [V]?

In the I/O tab you have the option to change the settings for both the analog inputs and outputs. There is also an option to manually adjust the output signal, this could for instance be needed during commissioning of an application.