In the fields of HVAC, refrigeration, and building automation, CAREL's PCO series programmable controllers are widely used in chillers, heat pumps, air conditioning terminals, and refrigeration equipment. The PCO/PCOT series text controller, which is matched with it, serves as a human-computer interaction interface and has long been responsible for functions such as parameter viewing, setting value modification, and alarm display. However, with the gradual discontinuation of PCO/PCOT series products and the increasing demand for graphical interfaces and multilingual support from users, alternative solutions have become an urgent need.
The PGD graphic handheld devices (PGD0000N00, PGD1000N00, PGD1000NW0, etc.) launched by CAREL are designed to solve this problem. It is fully compatible with older PCO/PCOT terminals, supporting graphical icon display, international fonts, and a wider operating temperature range (-20~60 ℃), while retaining the original communication protocol and wiring methods. Starting from the perspective of on-site replacement and debugging by engineers, this article systematically outlines the installation steps, address configuration, PLAN network communication settings, and common troubleshooting methods for PGD handheld devices, helping users quickly and safely upgrade and replace old terminals.
Overview and Selection Comparison of PGD Handheld Devices
1.1 Product positioning and compatibility
The PGD series graphical controller is a remote human-machine interface designed specifically for CAREL PCO controllers. Its biggest feature is full backward compatibility with old PCO/PCOT text terminals, which means:
No need to modify the application software on the PCO motherboard.
The communication protocol (such as PLAN, point-to-point) and physical interface (RJ12 telephone line) remain unchanged.
The original wiring and installation hole sizes are basically compatible, only minor adjustments are needed.
Therefore, when the old terminal on site experiences screen aging, button failure, or needs to be upgraded to a graphical interface, PGD is an ideal direct replacement product.
1.2 Model Code and Selection
According to display size and backlight color, the PGD series is divided into the following main models:
Model Code Display Pixel Backlight Color Applicable Scenarios
PGD0000N00 120 × 32 green simple text and basic icon, replacing PCO/PCOT
PGD1000N00 132 × 64 green larger display area, supporting richer icons
PGD1000NW0 132 × 64 white is the same as 1000N00, with a softer white backlight
In addition, there is a PGDN version without buttons and LEDs, which requires an external membrane keyboard (up to 8 keys+3 LEDs). In conventional replacements, integrated models with buttons are more commonly used.
1.3 Key Characteristics
Graphic management: It can display pre-defined icons in application software and support international fonts (5 × 7 or 11 × 15 pixels).
Wide temperature range: -20 ℃~60 ℃, suitable for harsh environments such as refrigerated warehouses and outdoor cabinets.
No local program: The handheld device itself does not require downloading programs, and all screen logic is defined by the PCO motherboard and automatically adapts after replacement.
Communication interface: RJ12 (6P6C) telephone line interface, the maximum communication distance depends on the PLAN network capability of PCO (usually up to several hundred meters).
Mechanical installation and electrical wiring
2.1 Requirements for panel openings
The PGD handheld device is designed for embedded panel installation and fixed with welded column head bolts. The installation panel thickness should be at least 2mm to ensure that the display area is not obstructed by panel deformation.
Hole size (refer to catalog Fig.8, Fig.9):
PGD0 series (120 × 32): Panel opening 78 × 30mm.
PGD1 series (132 × 64): Panel opening 74 × 39mm.
In addition, a small hole (at least 40 × 10mm) needs to be opened on the installation panel for flat cables to pass through. This flat cable is used to connect the internal button circuit of PGD (only when using models with buttons). When wiring, pay attention to protecting the cable to avoid being cut by metal edges.
2.2 Electrical connection steps
Power off operation: Before making any wiring, ensure that both the handheld device and the PCO motherboard are powered off.
Connect the flat cable: Insert the flat cable at the back of the handheld device into the PGD dedicated interface, paying attention to polarity. Pin 1 is marked with a "D" symbol in the interface.
Connect RJ12 communication cable: Use a standard telephone type cable (CAREL S90CONN00 * series or self-made cable), with one end inserted into the RJ12 interface behind the PGD and the other end inserted into the corresponding terminal interface of the PCO motherboard (usually labeled as "TERM" or "PGD").
Power on inspection: Connect the PCO motherboard power supply, and the PGD should automatically start and display the default interface or "NO LINK" to establish communication.