Main Page

This Wiki is for users of UBC's Multi-Channel Electronics (MCE), including the MCE Acquisition Software (MAS).

MCE Overview

The MCE described here borrows heavily from the designs used at NIST. Changes have been made to upgrade components, achieve higher integration, and match to the specific experimental configurations.

In basic operation, one MCE subrack controls the SQUID amplifiers and multiplexer, and reads signals from one 32×41 pixel or 16×41 pixel sub-array. The system hardware is completely modular at the sub-array level. Each sub-array is connected via woven cryogenic cables to a single MCE subrack through 3 or 5 MDM connectors. Each MCE subrack is, in turn, connected by an optical fibre to a single data-acquisition PC running Linux and data-acquisition software (MAS) developed at UBC.

Each MCE consists of hybrid analog/digital hardware and firmware developed for Altera Stratix FPGAs. A subrack has up to nine cards: including 2 or 4 Readout cards each of which reads 8 output columns through 14-bit 50MHz ADCs; 1 address card to multiplex the first-stage SQUIDs biases at around 20kHz; 1 clock card to interpret commands and to synchronize all the cards using a 25MHz clock; 2 or 3 bias cards to control the SQUID series-array feedback, the second-stage SQUID bias and feedback as well as the bolometer bias and heater. During detector setup, the MCE is used to calculate the optimal operating points for the bolometers and the SQUID amplifiers by measuring their characteristics using open and closed feedback loops. During observation, MCE uses a running PID-calculation to determine the first-stage SQUID feedback necessary to keep the whole amplification chain in a linear regime.

In conjunction with the MCEs, a Sync Box supplies data-valid pulses with serial numbers to all MCE subracks and to the telescope pointing system. This allows synchronization between the data acquisition, the pointing system, and the telescope housekeeping.

Documentation

• MCE Hardware - information on MCE hardware (and accessories)
• MCE Firmware - firmware versions, features, and tools (including sync box and PCI card firmware)
• MAS - the MCE Acquisition Software - kernel driver and low-level tools
• MCE script - SQUID array setup programs
• MCE usage - practical usage and reference documents

Contact Info

The mce-announce e-mail list is used to communicate important firmware and software updates to the MCE user community. You can subscribe to it by visiting:

https://listserver.phas.ubc.ca/mailman/listinfo/mce-announce

MCE Lab:                   604-822-2585
Halpern's Lab:             604-822-6709

Hardware/firmware:         mandana at phas.ubc.ca
Software:                  mhasse at astro.princeton.edu, dvw at phas.ubc.ca
 
Department of Physics & Astronomy 
University of British Columbia
Hennings 204, 6224 Agricultural Rd.
Vancouver, BC V6T 1Z1 
Canada