🛠 TEARDOWN: Erqos EQSP32CE PLC (Ethernet version)
Intro
Let's look inside the modern user-friednly PLC based on the ESP32-S3 SoC.
Specs
- Model: EQSP32CE
- MCU: ESP32-S3-MINI-1
- Ethernet: W5500
- Interfaces (non-isolated): RS485 or RS232; CAN
- Alarms: 4 LEDs, Buzzer
- Supply Voltage: 7-26VDC
- Output Voltage: 5V 1A
- Operating Temperature: -20 °C to +55 °C
Official Site
Expansion Principe
02x05 2.54mm pin socket connector on the right side, I2C interface:
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Teardown
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Housing
To dissassemble it you need to remove stickers and unscrewed two screws.
This module is cheap Chinese, so soldering quality is moderate, but the most important is that all RJ45 pins are SMD.
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Boards
- FR-4
- ENIG
- H=1.6mm
Components
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Schematic Solutions Analysis
| To protect device against reverse polarity it has diode on positive input. |
| High power of PWM by using low-side switch (intelligent FET), which accept 3.3V/5V logic and have some sort of protections. |
| To make possible sampling 4-20mA current MCU need to enable 470 Ohm 0805 resistor by using N-FET on NPN-BJT |
| To measure up to 10V it has voltage divider. |
Conclusions
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| 🔴 | Connection between main board and Ethernet board have poor mechanical connection |
| 🔴 | Device uses W5500 module with SMD RJ-45 (Ethernet) connection, which have poor mechanical stability and low quality soldering (bad solder) |