Cabinet Monitor Design Specification

1 Overview

This document describes hardware design specification of the Cabinet Monitor, which is used in SV 1.5T MRI system.

1.1 Purpose

The Cabinet Monitor shall monitor the leakage from the cooling system, the temperature in the cabinet, water tank level and flow of the cooling system. The Cabinet Monitor shall drive relay driver, Emergency Stop, if necessary. The Cabinet Monitor shall communication with SCP via CAN.

1.2 Function Overview

Power Supply

  • Main Power Supply Switch ・・・Cabinet Monitor Main Power

  • Fuse ・・・M, 3A/250V, replaceable fuse folder

Interface

Cabinet Monitor Board has the following interfaces.

  • Leakage Sensor (2, 3)

    • Leakage ・・・leakage signal input

    • sensor fault ・・・sensor fault signal input

  • Temperature Sensor (1, 2)

    • OUT1 ・・・temperature sensor out1 input

    • OUT2 ・・・temperature sensor out2 input

  • Water Level Sensor ・・・Water Tank Level signal input

  • BRM PUMP Status ・・・BRM Pump Status signal input

  • Cabinet PUMP Status ・・・Cabinet Pump Status signal input

  • Standby Mode ・・・Standby Mode signal(RS422) input

  • CAN ・・・Board Control interface

  • E-off ・・・Relay control signal output (RelayDriver2)

  • Standby ・・・Relay control signal output (RelayDriver5)

  • Magnet Monitor Output ・・・Relay point output(Relay6)

2 Configuration

This main configuration of the Cabinet Monitor should consist of three power supplies (24V, 5V and isolated 24V for CAN), three leakage detectors, 6 relay drivers and 14 LEDs. The Cabinet Monitor can monitor leakage and sensor fault by each leakage detector, over temperature by two Temps Sensor (GEHC P/N 2184426), flow SW and tank level SW of Cooling Unit. The Cabinet Monitor can drive the 6 relay drivers. It has 14 Input ports for sensors. The Cabinet Monitor has a CAN communication port and supply 24V DC power, which can communicate with SCP by CAN.

The assemblies that make up the cabinet monitor are as follows.EMI filter: filter the input 120VAC power supply. AC-DC output power supplies( 120VAC to 24VDC, 120VAC to CAN 24VDC, 120VAC to 5VDC, and 5VDC to 3.3VDC) The sub-assemblies supply power for the whole cabinet monitor. Cabinet monitor control board: process the I/O signals and drive relay dirvers CAN Communication Core Board assembly: the channel of CAN communication with SCP Leak sensor Amplifier board (3 pieces): detect the leak sensors status, leakage and disconnection.

Figure 1. Block Diagram of the Cabinet Monitor Board

In this illustration, the Leakage Sensor1, Primary Trans, DCERD2 PS and LK1 LED SF1 LED are not used in SV system.

3 Electrical Specification

3.1 Power Voltage

The AC120V shall be provided from the Cabinet. The DC24V or DC5V switching power supply in the Cabinet Monitor shall provide DC24V or DC5V to the board, sensors, relays and CAN power. CAN power supply should be isolated from another power supply.

Figure 2. Block Diagram of the Power Supply

FG of the Power Supply shall be connected with the chassis and also each switching power supply shall be connected with the chassis by a frame or a spacer.

Figure 3. FG Connection

3.2 LED indicator

This table shows the LED indicators on the front panel.

3.3 Connection with Interface

This section explains the interface connection of the Cabinet Monitor.

3.3.1 Leakage Sensor1(Mini Mete-N-Lok, 3pin) (not used)

3.3.2 Leakage Sensor2(Mini Mete-N-Lok, 3pin)

3.3.3 Leakage Sensor3(Mini Mete-N-Lok, 3pin)

3.3.4 Temperate Sensor1, Left Cabinet

3.3.5 Temperate Sensor2, Right Cabinet

3.3.6 BRM PUMP status(Mini Mete-N-Lok, 2pin)

3.3.7 Water Level Sensor(Mini Mete-N-Lok, 3pin)

3.3.8 Cabinet PUMP Status(Mini Mete-N-Lok, 2pin)

3.3.9 Standby Mode(D-sub 9pin, Receipt)

3.3.10 CAN1(D-sub 9pin, Receipt)

3.3.11 CAN2(D-sub 9pin, Plug)

3.3.12 Relay Drive (D-sub 15pin, Receipt)

3.3.13 Magnet Monitor Out(Mini Mete-N-Lok, 2pin)

4 Board Electrical Specification

4.1 Power Voltage

The Switching Power Supply(VS10C-5) provide DC5V to the board and the Cabinet Monitor Board produces DC3.3V. The power voltage(DC5V,DC24V,CAN DC24V) shall be isolated and then provide to the each device.

  • LOGIC Power ・・・・・・・・・・・DC5V,DC3.3V,DC±12V

  • CAN Power ・・・・・・・・・・・DC24V

  • Leakage Sensor/Relay Power ・・・・DC24V

    * DC±12V shall be isolated electrically

Figure 4. Board Power configuration

4.2 Connection

In this section, the following shows the connection with Cabinet Monitor Board.

4.2.1 Power Connector(J1)

4.2.2 CAN Power Connector(J2)

4.2.3 CCC Board Connector(CN1)

4.2.4 Leakage Sensor Connector(J3)

4.2.5 Temperate Sensor1(Left Cabinet) Connector(J4)

4.2.6 Temperate Sensor2(Right Cabinet) Connector(J5)

4.2.7 Alarm Connector(J6)

4.2.8 Water Level Connector(J7)

4.2.9 LED Connector1(J8)

4.2.10 LED Connector2(J9)

4.2.11 Relay Drive Connector(J14)

4.2.12 Magnet Monitor Out Connector(J13)

4.2.13 Standby Mode Connector(J11)

4.2.14 CAN SIGNAL INPUT CONNECTOR (CN3)

4.2.15 CAN SIGNAL OUTPUT CONNECTOR 1(J10)

4.2.16 CAN SIGNAL OUTPUT CONNECTOR 2(J12)

4.2.17 CPLD JTAG CONNECTOR(CN2)

5 Function Specification

5.1 Reset Circuit

There is a Power ON Reset Circuit for CPLD on the Cabinet Monitor Board. The following figure shows the block diagram.

Figure 5. Reset Circuit Block Diagram

※ Delay time can be calculated 220 milliseconds = 10Kohm(Resistance) X 10uF(Capacitance) X 2.2(Constant Value)

5.2 Power Monitor Circuit

There are four voltage monitors(3.3V ・5V ・24V ・24V(CAN)) circuit on the Cabinet Monitor Board.

3.3V and 5V monitor are used 2 lines Op-Amp and 24V ・24V(CAN) monitor are used Analog Photo coupler, because 24V・24V(CAN) power should be isolated.

5.3 Leakage Sensor

The following shows the block diagram of the leakage sensor.

Figure 6. Leakage Sensor Block Diagram

5.4 Temperature Sensor

The following shows the block diagram of the Temperature sensor.

Figure 7. Temp. Sensor Block Diagram

5.5 Alarm Circshuuit(TANK,PUMP)

The following shows the block diagram of the Alarm Circuit.

Figure 8. Alarm Circuit Block Diagram

5.6 Standby Mode

The following shows the block diagram of the Standby Mode.

Figure 9. Standby Mode Block Diagram

5.7 Magnet Monitor Out

The following shows the block diagram of the Magnet Monitor Out.

Figure 10. Magnet Monitor Out Block Diagram

5.8 Relay Drive(1-5)

The following shows the block diagram of the Relay Driver. Output signal shall be isolated by photo coupler before relay driver.

Figure 11. Relay Drive(1-5) Block Diagram

5.9 CAN INTERFACE

The following shows the block diagram of the CAN Interface. CAN signal from CCC Board connect with two D-sub 9 pin. And CAN DC 24V also shall be provided.

Figure 12. CAN Interface Block Diagram

5.10 Node-ID DIP Switch

The following shows the block diagram of the CAN Node-ID. The Node ID shall be selectable by this DIP-SW. The Cabinet Monitor Node ID shall be set to 12((H)01100(L)).

Figure 13. Node-ID DIP-SW