Debugging and maintenance of EPSON RC90/RC90-B controller

EPSON RC90/RC90-B Controller: Complete Guide to Installation, Debugging, and Troubleshooting

In industrial robot applications, stable operation and fast fault handling of controllers are key to ensuring production efficiency. The EPSON RC90/RC90-B robot controller is designed specifically for LS series SCARA robots, supporting EPSON RC+7.0 software environment, providing 4-axis AC servo control, rich I/O interfaces, and multiple optional communication modules. This article is based on the RC90/RC90-B controller hardware manual, systematically explaining its installation specifications, cable connections, operating modes, development environment configuration, safety circuit wiring, I/O remote signal settings, daily maintenance, and typical troubleshooting methods, providing a practical technical guide for on-site engineers.

Product Overview and Safety Notice

RC90 and RC90-B are EPSON's RC90 series robot controllers, with the main differences being the type of I/O output circuit and some hardware layouts. Both use 32-bit microprocessors to control up to 4 AC servo motors. The standard I/O is 24 point input/16 point output (can be remotely assigned), and Ethernet (100BASE-TX/10BASE-T), RS-232C, and USB interfaces are standard. It supports developing PCs through USB or Ethernet connections.

Core security principles:

The controller contains high-voltage capacitors inside, and after power failure, it must wait for 15 minutes before opening the hood.

The emergency stop switch and safety door input must use dual redundant normally closed contacts and be correctly connected to the EMERGENCE interface.

Before operating the robot at any time, it is necessary to confirm that the safety protection device is effective.

The manual repeatedly emphasizes that only trained and qualified personnel can install, program, and maintain this equipment. Any act of plugging or unplugging cables while the power is on may result in electric shock or equipment damage.

Hardware installation and environmental requirements

2.1 Installation direction and spacing

The RC90/RC90-B controller is designed for cabinet wall hanging or desktop upright installation (see installation diagram). To ensure heat dissipation, it is necessary to:

Reserve a ventilation space of 100mm on the top, bottom, left, and right sides of the controller.

The installation direction must ensure that the air inlet and outlet are unobstructed (air inlet below the front panel, air outlet at the back and above).

Do not install the controller near a heat source or in direct sunlight.

2.2 Environmental conditions

Environmental temperature: 5-40 ℃

Relative humidity: 20% to 80% (without condensation)

Pollution level: 2 (compliant with IEC 61800-5-1)

Altitude: ≤ 1000 meters (downgrading is required for use above 1000 meters)

2.3 Power Requirements

RC90/RC90-B is powered by single-phase 200-240 VAC and has a maximum rated capacity of 2.5 kVA (depending on the connected robotic arm). Specific peak current: about 70 A (2 ms) at the moment of power on, and about 50 A (2 ms) at the moment of motor connection. Leakage circuit breakers or circuit breakers rated at 15A or below must be installed, and it is recommended to use inverter compatible leakage protectors to avoid high-frequency leakage current tripping.

Cable connection and wiring specifications

3.1 Main Interface Description

Interface Function Remarks

The AC IN 200-240 VAC power input terminal must be grounded (green/yellow wire)

M/C POWER Robot Arm Main Power Supply (20 Pin) Special Cable

M/C ignal mechanical arm encoder signal (36 pin) dedicated cable

Emergency stop, safety door, latch release D-sub 25 pin

If the TP port is not connected to the teaching device or bypass plug, the bypass plug must be inserted

USB (development) connected to PC (EPSON RC+7.0) USB 2.0, maximum length 5 m

LAN Ethernet communication (RJ45) 100BASE-TX/10BASE-T

I/O connector standard I/O (24 inputs/16 outputs) D-sub 50 pin

RS-232C standard serial port D-sub 9-pin

Memory port USB memory (for state storage) only supports USB 2.0 flash drives

3.2 Key Wiring Precautions

Power grounding: The green/yellow wire of the power cord must be connected to the factory grounding terminal, with a grounding resistance of ≤ 100 Ω.

Mechanical arm connection check: The front of the controller is labeled with a "connection check label", which must be matched with the corresponding serial number of the mechanical arm. Incorrect connections can lead to abnormal or even dangerous robot movements.

EMERGENCE interface: The 24V output of this interface is only used for emergency stop circuits and cannot be used for other loads. The emergency stop switch must use a dual contact normally closed switch, with two contacts connected to pins (1-2) and (14-15) respectively, and voltage read back at pins (3-4) and (16-17). If two redundant input states are inconsistent for more than 2 seconds, the controller will report a fatal error and lock.

TP port: If the teaching pendant (TP1/TP2) is not used, the accompanying bypass plug must be inserted, otherwise the controller will always be in emergency stop state.

Operation mode and switching