CERN ELMB (Embedded Local Monitoring Board) is a multi-function device
that is focused on providing analog inputs/outputs, digital
inputs/outputs, SPI connectivity and custom functionality, being
controlled by CANbus.
Currently, at CERN, it is used by:
The total count of ELMB in operation at CERN is of around 10000.
ELMBs have been carefully tested for operation under specified doses of
The groups behind ELMBs are: CERN ATLAS Central DCS, NIKHEF, CERN
The main contact point for ELMB is CERN ATLAS Central
Please see Annex B. of ELMB User Guide in "Documents" tab for source.
AVR RISC architecture ATMEL Atmega128
128 Kbytes of on-chip flash memory,
4 Kbytes of SRAM,
4 Kbytes of EEPROM,
In-System Programming via CAN bus
Full CAN controller interface with PCA82C250
6 bit CAN identifier and 4 baud rates supported
3-wire SPI interface
Real Time Counter with a separate 32 kHz crystal
8-channel 10-bit ADC I/O lines available2
6 external interrupt inputs
Port A 8 digital bi-directional I/O lines (can alternatively be used
for external SRAM).
Port C 8 digital output lines (can alternatively be used for
Port D 5 digital bi-directional I/O lines
Port E 5 digital bi-directional I/O lines
Port F 8 digital input lines or 8 analog inputs for the ADC
Strobe and enable lines for external SRAM
Separate regulator for the CAN bus transceiver and optocouplers
Regulator for the microcontrollers
Voltage converter 3.3V to 5.4V
Optional Delta-sigma ADC CRYSTAL CS5523 with 64 channel multiplexer
6 bipolar or unipolar input ranges from 25mV to 5V
100 pA input current on 25mV, 55mV and 100mV
10nA on 1V, 2.5V and 5V ranges
8 conversion rates from 2 Hz to 100Hz
64 channel multiplexer
+5V and -5V on board power regulators
The size of the printed circuit board is 50x67mm.
The board is equipped with two connectors with 100 pins.
Please note that in known designs ELMBs get plugged in into:
standard ELMB motherboards which provide versatile analog and
digital input/output configurations
custom motherboards tailored for specific areas, in which an ELMB
often does not play a main role, but is just local monitoring unit