SDS Telemetry System

SDS DHPS board picture
SDS Simple Telemetry circuit board (STB)

SDS DHPS board picture
SDS Downhole Power Supply circuit board (DHPS)


        The SDS Telemetry System consists of a Simple Telemetry Board (STB) and an optional Downhole Power Supply Board (DHPS).


SDS Simple Telemetry Board (STB)


        The purpose of the STB is to convey data from downhole tools on the tool bus (RS232), Transmit/Receive the data and Commands to/from the surface via a reliable digital telemetry system facilitating communication between the Warrior Surface System and downhole tools. Typical applications have been for conventional logging tools (including digital acoustic and spectral data), hybrid tools (telemetry and memory simultaneously), intervention tools (relying heavily on surface to downhole control) and fast mobilization for the development of new tools and sensor testing where "off the shelf" and simple to setup and interface telemetry can save substantial development time and costs.


        General Specifications: Maximum Temperature 350ºF (177°C), operating Voltages (dependent on power supply) range +0 +450V DC, Current consumption at 200V 15mA, Tool Bus data rate 115kbps, Wireline Uplink data rates currently 12 kbps to 67 kbps, and Downlinks rates 1 kbps to 5 kbps. Input Voltage Requirements are typically +15Vdc, -15Vdc and +5Vdc.


        The STB consists of 5 main functional blocks as shown in the block diagram below.

  SDS STB picture  

Wireline Uplink Modem:

        The Wireline Uplink Modem forms the hardware interface between the Rx Tool Bus RS232 Modem and the Wireline mono-cable which transmits data to the surface system. Uplinks are modulated onto the line as pulsed RS232 at a selectable bit rate currently ranging from 12 kbps to 67 kbps with amplitude of +/- 15Vpk. The Wireline Uplink Modem rate can be changed via downlink command. The Wireline Uplink Modem uses half duplex transmission.

Rx Tool Bus RS232 Modem:

        The Rx Tool Bus RS232 Modem forms the hardware interface between the Downhole Tools and Wireline Uplinks Modem. Rx is modulated TTL input (5Vdc), onto Rx Tool Bus RS232 Modem at 115kbps. The Rx Tool Bus RS232 Modem rate can be change for downlinks commands via I2C Bus.

Wireline Downlink Modem:

        A half duplex downlink allows the user to configure and control operations from the surface prior to and during logging. Control is exercised by means of commands, which may be destined for the Wireline Downlink Modem, Rx Tool Bus RS232 Modem, and /or passed on to other tools via the Tx Tool Bus RS232 Modem. Where command execution generates a response, this is generally uplinked to the surface via Wireline Uplinks Modem, downlink status is monitored and reported by the system.

Tx Tool Bus RS232 Modem:

        The Tx Tool Bus RS232 Modem forms the hardware interface between the Wireline Downlinks Modem and the Downhole Tools. Tx is modulated TTL output, onto the Tool Bus as RS232 at 115kbps (5Vdc). The Tool Bus rate can be changed for downlinks commands via I2C bus.

Analog Bus Inputs:

        The Analog Bus Inputs received signals between 0 to 4 VDC. The Tool Head Voltage and Tool Bus Voltage are sensed and sent to the surface to facilitate setting the appropriate operating voltage.


SDS Simple Telemetry Board Specification:

Parameters: Values:
Uplink Data Rate over Wireline 50 Kbits/sec (on most cables); actual rate controlled from surface
Downlink Data Rate over Wireline 5 Kbits/sec
Tool Bus RS232 serial port at logic levels (3.3V to 5.0V); rate configurable but aggregate must be lower than the selected wireline rate.
Power Requirements Plus/minus 12VDC to 15VDC and +5VDC
Temperature Rating 175°C (347°F) for 1 hour
Board Dimensions 7.5 inches x 1.25 inches

SDS Downhole Power Supply (DHPS)


        The power supply is a discontinuous mode (DCM) flyback DC- DC converter. It works by storing energy in the flyback inductor during the switch’s on-time and releasing this energy to the secondary circuits during the switch’s off-period. The power transformer, in the case of a flyback converter, is not a transformer at all. Transformers work by coupling energy from primary to secondary, storing as little energy as possible. The flyback, however, stores all the energy for one cycle of operation in what is properly an inductor.

  SDS DHPS Block diagram picture
Downhole Power Supply Block Diagram

        The nominal input voltage (Line) is 200VDC, with a range 180VDC to 250VDC. The switching frequency is set to 100 KHz, and the output voltage is 24VDC/1.5A. The power supply has over output voltage and current protection circuits; the overvoltage circuit is setup by D10, D1, and Q1 to avoid voltage more than 26VDC. And the over current is setup by RS1, and PMW controller Pin 4 to avoid more the 2Amps.

There are three high efficiency synchronous step-down regulators. The input voltage is 24VDC and the outputs voltages are +15VDC@100mA, -15VDC@100mA, and 5VDC@200mA.

The Cable Head Voltage (LINE) is sample (200_S) @2VDC. The Tool Power Bus Voltage is sample (24_S) @ 2.4VDC, those outputs signal are sensed by the telemetry board.


SDS Power Supply Board Specification:

Parameters: Values:
Head Voltage (Input) 180-270 VDC
Outputs Plus/minus 15VDC @ 100ma and +5VDC @ 200ma (normally for telemetry board) 24VDC @ 1.5A general purpose. Higher output is possible with use of chassis mount components.
Temperature Rating 175°C (347°F) for 1 hour
Board Dimensions 10 inches x 1.25 inches

For pricing and availability. Please contact us for more details.