IS210SAMBH1A - Control Acoustic Monitoring Terminal Board

Functional Description

IS210SAMBH1A is a Control Acoustic Monitoring Terminal Board manufactured and designed by General Electric as part of the Mark VIe series used in GE Distributed Control Systems. The Mark VIe Control Acoustic Monitoring (SAMB) terminal board is a duplex terminal board providing 18 inputs for the Acoustic Monitoring System. The SAMB provides two terminal points per input channel for 18 channels on 36 terminals. It also provides an additional 18 buffered outputs on 36 terminals to connect external instrumentation for monitoring the AC voltage signal that represents the dynamic pressure signals from the combustor. SAMB includes passive electromagnetic interference (EMI) filters to protect against very high-frequency noise generated by external sources. SAMB includes the following features:

• Eighteen signal interface channels for acoustic monitoring, supporting duplex configuration.
• Channels 1 – 9 are configurable to support PCB Piezotronics constant-current charge amplifiers or charge converter signal amplifier (CCSA) outputs. Sensor power for the PCB sensors is independent of the sensor power for channels 10 – 18.
• Channels 10 – 18 are configurable to support PCB Piezotronics constant-current charge amplifiers or CCSA outputs. Sensor power for the PCB sensors is independent of the sensor power for channels 1 – 9.
• Eighteen buffered outputs provide ac signal content of the dynamic pressure signals without DC bias voltage
• Thirty-six Euro-style box-type terminal blocks for the customer inputs
• Thirty-six Euro-style box-type terminal blocks for the buffered outputs
• EMI protection for all inputs
• EMI filtered inputs fanned to the A and B slots

Installation

The SIGx line for the PCB sensors is connected to the continuous current supply via hardware jumpers. JPx hardware jumpers are present on each channel (where x equals the input number). To use the GE CCSA for Endevco sensors or any other voltage output device, the jumper must be in the CCSA position. When using a PCB sensor or any other current output device, the jumper should be in the PCB position.

Operation

The SAMB inputs an ac voltage signal from the CCSA proportional to the dynamic pressure sensed by either an Endevco or PCB probe. SAMB also inputs the dynamic pressure directly from a PCB constant-current charge amplifier connected to a PCB probe as an ac voltage proportional to the combustion dynamics riding on a dc bias voltage. Each channel provides a 3.6 mA constant-current source that can be connected to SIGx (where x is the channel number) for the PCB charge amplifiers. The jumper JPx (where x equals the channel number) is a two-pole jumper that controls the constant-current power supply and whether RETx is tied to the power ground, PCOM. When JPx is in the CCSA position, the constant-current is disabled and RETx is not tied to PCOM. When JPx is in the PCB position, the constant current is connected to SIGx, providing approximately 3.6 mA of current to power the PCB charge amplifier. The RETx line is tied to PCOM to provide a return path for the constant current.