SAIA-Burgess PCD7.D900

The SAIA-Burgess PCD7.D900 is a legacy industrial Graphic Display Terminal (HMI) from the Saia PCD (Process Control Device) family.¹ It was widely used in building automation and HVAC systems to provide a local interface for Saia’s modular PLCs.

Below is the technical description and key features of this model:

1. Display and Visuals

• Type: Monochrome Graphical LCD (Liquid Crystal Display).²

   

• Resolution: $128 \times 240$ pixels, which was quite advanced for its time, allowing for both text and basic graphics/icons.

• Backlight: Equipped with a backlight for visibility in dark control cabinets.

• Format: It can display multiple lines of text or simple process diagrams (like fans, pumps, or valves).

2. Physical Interface (Keypad)

The PCD7.D900 is a Keypad-operated HMI rather than a touchscreen.³

• Tactile Keys: Features a set of physical buttons for navigation and data entry.

• Function Keys: Includes user-programmable function keys that allow operators to jump to specific screens (like “Alarms” or “Setpoints”) with a single press.

• Numeric Entry: Dedicated keys for changing values like temperature setpoints or timer durations.

3. Connectivity and Integration

This unit is specifically designed to work within the Saia Burgess PCD ecosystem:

• Connection: It typically connects to the PCD1, PCD2, or PCD4 series controllers via a dedicated serial interface (often RS-232 or the proprietary Saia S-Bus).

• Power: Usually powered directly from the controller or a 24V DC supply.⁴

   

• Programming: Configured using the Saia PG5 Controls Suite (HMI Editor), where the screens are linked to the PLC’s “Registers” and “Flags.”

4. Technical Specifications

5. Maintenance and Status (Legacy Hardware)

The PCD7.D900 is now a Legacy/Discontinued product.⁵

• Spare Parts: Because they are no longer in production, these are mostly available as refurbished or “New Old Stock” (NOS).

• Battery: Like many Saia products of that era, check the internal battery if the unit loses its time or saved parameters during a power failure.

• Replacement: Modern replacements usually involve the Saia PCD7.D4 series or Web-HMIs, which require a transition to HTML5-based visualization.

Summary:

The PCD7.D900 is a rugged, “industrial-strength” text and graphics terminal. It is famous for its long life in boiler rooms and air handling unit (AHU) control panels.

Would you like me to help you find the “Serial Pinout” to connect this to a PCD2 controller, or are you trying to troubleshoot a specific “Communication Error” on the screen?