VARIAN E15000591 PLC PCB Assembly 132102
The VARIAN E15000591 is a printed circuit board assembly (PCA) designed for PLC control within VARIAN’s vacuum equipment, specifically the HeliTest and VS series leak detectors, as well as Turbo-V pumps and multi-sensor controllers. The board carries the internal reference number 132102 and acts as the central logic unit for process sequencing, sensor acquisition, and actuator control.
Functional Overview
This PCB is built around a 16-bit microcontroller (Freescale MC68HC912) running at 16 MHz. It provides onboard memory: 64 KB EEPROM for firmware, 32 KB SRAM for runtime data, and 2 KB FRAM for retentive parameters. The board handles digital I/O (16 inputs, 16 outputs, optically isolated) and four analog input channels (0–10V, 12-bit resolution).
Power and Interfaces
The board requires +5V DC (200 mA) and +24V DC (150 mA) for the I/O section. Connectors: two 34-pin IDC headers for external I/O modules, a 9-pin D-sub for RS-232 communication (9600 bps, service port), and a 6-pin mini-DIN for a proprietary VARIAN programming keypad. An LED status array (8 LEDs) indicates power, error codes, and I/O activity.
Environmental and Physical
Dimensions: 165 mm x 100 mm. Thickness: 1.6 mm, FR-4 material with ENIG finish. Operating temperature: -20°C to 70°C. Storage: -40°C to 85°C. The board is conformally coated for resistance to condensation and mild corrosive gases. It is mounted on four M3 standoffs.
Firmware and Diagnostics
The onboard firmware (version 3.1 as of E15000591) controls the vacuum pump sequence, pressure thresholds, and safety interlocks. The board has a watchdog timer and brown-out detection. A 3-pin header allows in-circuit programming via BDM (Background Debug Mode). Diagnostic pulses on the status LEDs flash error codes (e.g., 2 flashes = EEPROM CRC error).
Compatibility and Spare Use
This PCB is a direct replacement for original VARIAN part numbers E15000590, E15000592, and 132102-001. It is compatible with controllers: VS Series (VS12, VS15), HeliTest (HIT 30, 45), and multi-gauge controllers (MGC-2). The board is supplied without the I/O terminal blocks (available separately).
Installation Notes
Before installation, verify that the power supply is disconnected. Remove the faulty board, transfer the EPROM (if applicable) from the old board to the new one for retaining calibration data. The board has no user-configurable jumpers; all settings are stored in the firmware. Torque screws to 0.5 Nm.
Typical Applications
Used in semiconductor vacuum coating equipment, analytical instruments, and research vacuum systems. The board controls pump down cycles, valve sequencing, and interlock logic for cryo and turbo pumps.
Ordering and Documentation
Part number: E15000591 (alternative 132102). The board is supplied in an anti-static bag with a dessicant. Technical reference: VARIAN Service Bulletin 87-900-501-01. RoHS compliant (lead-free since 2008).
