HMI OP 320 teardown
OP 320 HMI is a monochrome graphic panel with 20 configurable keys. It's supposed manufacturer is XINJE Electric Co, but there is not a visual reference in the case nor in circuit boards. Its aspect is very similar to KINCO MD204L.
*Este articulo tambien esta disponible en Español haciendo clic aqui
This HMI cost around 40 dollars (shipment included!), is powered by 24 V DC and have RS-232 and RS-422 communication interfaces, its programmed using the RS-232 port using a proprietary software. Have multiple industrial communication protocols. so is a very attractive solution to interface microcontroller based systems, because its integrated display, keyboard, control logic, using only a serial port, all encased in an "industrial like" case that the manufacturer claims to be IP65 for front panel.
To open the OP 320 case a 2.4 mm x 40 mm Phillips screwdriver is required
First, remove 24V power terminal and release the 4 screws that holds the back case. Then pull the main board to disconnect from the display board, the boards are connected to a 20 pin single line connector.
Carefully disconnect the membrane keyboard connector (9 pin single line). This allows to totally disconnect the main board. The last step is to remove the spacer and the 3 screws that hold together the display board with the front panel.
ELECTRONIC BOARDS AND MAIN COMPONENTS
|Scratched info||Microcontroller, looking the package and pin arrangement, probably an MCS-51 compatible with onboard RAM and FLASH|
|LM2576S-5.0||SWITCHER 3A Step-Down Voltage Regulator|
|SP202EEN||Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers|
|74HC245D||octal transceiver featuring non-inverting 3-state bus compatible outputs in both send and receive directions|
|7705AC||integrated-circuit supply-voltage supervisors|
|MAX 485||Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers|
|JXD 19264A||LCD 192 x 64 graphic matrix display|
|7660||Switched capacitor voltage converter|
In the following video the detailed HMI teardown process is presented