Teledyne ULTRAFLOW 150, Operation Manual, Page: 31 / 162

SECTION 5.0, TRANSDUCER INTERFACE ENCLOSURE
logic. Bus transceivers are used to convert logic from one level to another
wherever needed.
5.2.3.6 Purge Switch Circuits
The signals from the purge switch enter the Flow Mother Board through the
Preamp Board connector. They are passed through an ESD/buffer network to the
computer module. A logic LOW indicates normal purge air flow.
5.2.3.7 On Board D.C. Supplies
The Flow Mother Board has circuits to produce the following D.C. supply
voltages: 2.5 VDC---Used for FPGA Core functions; 3.3 VDC---Used for FPGA
I/O functions; 5.0 VDC---Used for analog functions; -5.0 VDC---Used for analog
functions; 130 VDC---Used for short range transducer bias.
5.2.3.8 External Serial Data Connections
The Flow Mother Board supports both synchronous and asynchronous serial
devices. All synchronous serial devices are for use by Ultraflow 150 components,
most of which are on TIE circuit boards external to the Flow Mother Board.
The Flow Mother Board supports one RS232C asynchronous serial port for use
with Teledyne Monitor Labs’ PC to Modbus software. This port is accessible
through DB9 connector J9.
5.2.3.8.1 Synchronous Serial Devices
The Flow Mother Board employs 11 synchronous serial device channels. The
Serial Peripheral Interface (SPI) standard is used to convey data to the I/O
devices. The Computer Module Board acts as the master SPI device and hence
controls access. All of the devices are on external circuit boards with the
exception of the real time clock. The devices are listed below.
1) Upstream Path A Preamp Gain
2) Downstream Path A Preamp Gain
3) Upstream Path B Preamp Gain (X Pattern only)
4) Downstream Path B Preamp Gain (X Pattern only)
5) Local User Interface LED Display (Optional)
6) Local User Interface Keypad (Optional)
7) Six Point I/O Analog Output DAC1 (Optional)
8) Six Point I/O Analog Output DAC2 (Optional)
9) Six Point I/O Isolator Inputs (Optional)
10) Six Point I/O Relay Outputs (Optional)
11)
Real Time Clock (Internal to Flow Mother Board
)
5.2.3.8.2 TIE Asynchronous Serial Port
Flow Mother Board DB9 connector J9 is an RS232C serial port. This is a three
wire serial port that does not support frame control. A custom Modbus protocol is
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