Debugging and maintenance of EPSON RC90/RC90-B controller

RC90/RC90-B supports three operating modes:

Mode Usage Safety Door Status Motor Power

TEACH teaching point data, can be manually opened by pressing the enable switch for low power

AUTO automatic running program must turn off high power

TEST low-speed program verification, the safety door can be opened or closed, and the low-power switch (T1 mode) needs to be pressed to enable it

Mode switching is achieved through the mode selection key switch of the teaching pendant. When switching from TEACH to AUTO, if the safety door is open and the latch release input is OFF, the controller will maintain the safety lock state. The safety door needs to be closed first, and then the latch release input (pins 18-19) needs to be closed before entering AUTO.

Engineering Tip: When using remote I/O control, the control device must be set to "remote" and the "AutoMode" output must be confirmed to be ON for remote input to be effective.

Develop PC connectivity and software settings

5.1 USB connection

EPSON RC+7.0 (recommended Ver. 7.0.2 or higher) must be installed first before connecting the USB cable to the controller and PC. If the order is reversed, Windows will pop up the "Add New Hardware Wizard", and you should click "Cancel".

Go to [Setup] → [PC to Controller Communications] in RC+, select "No.1 USB", and click Connect. After successful connection, the status will display "Connected".

When disconnecting, you should first click Disconnect in the software, and then unplug the USB cable, otherwise the robot will stop urgently.

5.2 Ethernet Connection

The factory IP address of the controller is 192.168.0.1, and the subnet mask is 255.255.255.0. The IP can be modified through [Setup] → [Controller] → [Configuration] of RC+. Note: from the firmware version Ver.7.4.8. x, if you use the global IP address to access the Internet, you must perform password authentication. For safety reasons, it is recommended to limit the use of the controller to the local area network (private IP address range).

5.3 Controller state storage function

The front panel of the controller has a USB memory port and a trigger button. Insert a compatible USB flash drive, wait for about 10 seconds for recognition, press the trigger button, and the controller will automatically package and save project files, robot parameters, I/O status, error history, etc. to the USB drive. When saved successfully, the TEACH, AUTO, and PROGRAMM LEDs will light up simultaneously for 2 seconds. This feature can be used for quick backup and remote support.

Emergency stop and safety circuit design

The EMERGENCE interface (D-sub 25 pin) is the core of security design. The key signals are as follows:

Pin signal description

1-2 ESW11, ESW12 emergency stop switch contact 1 (normally closed)

14-15 ESW21, ESW22 emergency stop switch contact 2 (normally closed)

3-4 ESTOP1+, ESTOP1- Emergency Stop Circuit 1 Input

16-17 ESTOP2+, ESTOP2- Emergency Stop Circuit 2 Input

7-8 SD11, SD12 safety door input 1

20-21 SD21, SD22 Safety Gate Input 2

18-19 SDLATCH1, SDLATCH2 latch release input

9, 10, 22, 23 24V output provides power for external emergency stop button

11,12,24,25 24VGND public area

Wiring points:

The emergency stop switch must be of the double pole double throw (DPST) normally closed type, with each pair of contacts connected to a redundant circuit.

The safety door switch also requires two sets of independent normally closed contacts.

The latch release input is used to release the latch state of the safety door open or TEACH mode. During normal operation, this input should be closed (ON).

All external emergency stop buttons should be connected in series in the ESTOP1/2 circuit, with a total circuit resistance of ≤ 1 Ω.

When the emergency stop is pressed, the motor power is immediately cut off, the dynamic brake short circuits the motor winding, and the robotic arm quickly stops. When restoring, you need to release the button first and then send the Reset command (which can be done through remote input or RC+menu).

I/O configuration and remote control signals

7.1 Standard I/O Electrical Characteristics (RC90 vs RC90-B)

The output of RC90 is a transistor type, which is fixed as a drain or source type when shipped and cannot be changed on-site. The rated output current is 100 mA/point, with a maximum of 30V. It is important to note that reversing the polarity may damage the circuit.

The output of RC90-B adopts a non-polar PhotoMOS relay with an average on resistance of 0.13 Ω, which can withstand loads up to 5A (resistive)/2A (inductive). Input voltage range 12-24V, ON voltage ≥ 10.8V, OFF voltage ≤ 5V, input current 3mA @ 24V.

7.2 Remote Input/Output Function Allocation

The initial state of the controller predefines 8 inputs (0-7) and 8 outputs (0-7) as remote functions, mapped as follows:

Input function and output function

0 Start 0 Ready

1 SelProg1 1 Running

2 SelProg2 2 Paused

3 SelProg4 3 Error

4 Stop 4 EstopOn

5 Pause 5 SafeguardOn

6 Continue 6 SError

7 Reset 7 Warning

Users can reassign these functions to different I/O points through RC+'s [Setup] → [System Configuration] → [Remote Control], or allocate functions to extended I/O or fieldbus modules.