aka Schlumberger Winch Data transfer to RigWatch (SLB to RW)

Operations Rationale

During logging operations, local convention widely distributes Schlumberger winch position (WPS). Tool string depth is a readily consumable gauge of both progress and status of logging operations.

System Overview

Schlumberger provides JRSO with winch position (WPS) telemetry. JRSO implemented SLB to RW software system to bring that data into RigWatch. The core of the SLB to RW system consists of WPS to WITS conversion. The system is presently running on a Dell laptop (SHIP-DAQ). The software system processes WPS telemetry through three serial devices:

• COM4 - Input. WPS telemetry is received via an RS485 serial connection from the Schlumberger rack.
  • The telemetry is a binary stream.
  • It is delivered at 19200 baud, 8 bits, no parity, 1 stop bit, no flow control.
• COM3 - Output. SLB to RW--a LabVIEW 2020 executable program--processes incoming WPS telemetry (COM4) to WITS format. The WITS stream is output via COM3 (RS232).
  • The decoded telemetry is readable text. No need to run PuTTy--SLB to RW displays the data stream.
  • It is delivered at 9600 baud 8 bits, no parity, 1 stop bit, no flow control.
• COM1 - SLB to RW output; RigWatch input.
  • PuTTY may be used to verify this output. While PuTTY has the serial port, RigWatch Master cannot see or use device "COM1 - Remote 6"
  • COM3 is physically connected in loopback fashion to COM1. The loopback cable is known as a null-modem or cross-over cable.
  • The data is delivered at 9600 baud, 8 bits, no parity, 1 stop bit, no flow control.

In operations the RigWatch Master receives WITS data on device "COM1 - Remote 6" (via the network) via the winch telemetry laptop aka  RigWatch Remote 6 aka 192.168.1.11.

Starting the Winch Telemetry Laptop

Cabling review

As-delivered, the COM-port wiring is placed as indicated

• COM4 is a National Instruments device RS-485 to USB.
  • The RS485 connector is tied to the Schlumberger WPS output.
  • The USB connector ties to the (only) left-hand-side (toward the back) USB connector.
• COM3 is provided via a Tripplite Keyspan USB to Serial RS232 device.
  • The USB cable ties to the (only) laptop backplane (right-hand-side) USB connector.
  • The 9-pin RS232 connector attaches to a null-modem cable.
  • The null-modem cable attaches to the only RS232 on the laptop backplane (left-hand-side).

Power up

1. A single deliberate press of the laptop power button suffices (upper-right of the built-in keyboard).
2. Login as DAQ. The usual.
   • SLB to RW is run automatically.
   • RigWatch is run automatically.
   • Windows profile startup processing takes precedent. It may be up to 30 seconds before SLB2RW and RW start.
   • SLB2RW will typically launch faster than RW.
   • If the Schlumberger winch feed is on, SLB2RW will begin displaying winch telemetry within 3 seconds.

Notes

• The DAQ profile is configured for Windows Remote Desktop access via 192.168.1.11.
• SLB to RW is installed in C:\Users\daq\Documents\WPS to WITS - SLB to Rigwatch: SLB2RW.exe
• RigWatch is installed in C:\RWPRO.
• The shortcuts used to launch both programs reside in C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Startup\.

Configure the RigWatch Master to receive WITS telemetry from RigWatch COM1 - Remote 6

WITS setup - at Krakatoa, not at Remote 6

An "SLB WITS Setup" should already be saved in the current RW setup file. If so, skip to "Running  SLB to RW".

1. Run RigWatch as usual.
2. Click Menu
3. Click the red "Setup" button
4. Click "Device Config" and enter the setup password
5. Click "Device Config" again
6. Scroll to "WITS Device 1" aka "wits1.dll" and select it
   1. If there is no "WITS Device 1", click in a "(no tool)" box then click "Add +"
   2. To add "WITS Device 1" scroll to near the bottom of the list and select "wits1.dll"
7. Set the following options
   1. Set Communications Port to "COM1 - Remote 6"
   2. Set Timeout Count to "10" (this is the default)
   3. Set speed to "9600/N/8/1" (these are the defaults)

WITS variable setup - at Krakatoa, not at Remote 6

1. Run RigWatch as usual.
2. Click Menu
3. Click the red "Setup" button
4. Click "Variables" and enter the setup password
5. Click "Variables" again
6. Use the "Page Down" button to scroll to the SLB Winch Variables

7. Confirm or set the following for each SLB variable

   Variable Number	Name	Input Device	Input Device Slot
   28 29 30	SLB Cable Depth SLB Cable Tension SLB Cable Speed	WITS Device1 WITS Device1 WITS Device1	0921 [MWDm] <Spare 1> 0922 [MWDm] <Spare 2> 0923 [MWDm] <Spare 3>

8. To change "Input Device", click on "Input Device", then scroll to and select "WITS Device 1"
9. To change "Input Device Slot", click on "Input Device Slot" and scroll to and select the appropriate WITS tag number. The number is the important part, but if you want to edit the label portion of the tag, refer to the RigWatch Manual.

Manual startup of RigWatch, SLB2RW

RigWatch and SLB to RW software may be launched from desktop or task bar shortcuts. Look for the following.

SLB to RW

(If RigWatch is in the way, minimize it by clicking "Key Pad", then "Minimize Rigwatch".)

Find SLB2RW, click.

Reviewing the (right-click) Properties of the shortcut will indicates where the software is located on disk.

The SLB2RW main window looks like this.

• If the winch telemetry is enabled, the data will update approximately once per second.
• "SLB Depth Serial Port" is COM4.
  (Changing it is not effective without also re-arranging the serial cables and recompiling the program.)
• "Output Stream" is Serial.
  (The network IP address option is not implemented.)

The "WITS Data String" reflects the "SLB Depth Data" but with tags applied to meet this WITS specification

RigWatch

(Verify that RigWatch is not previously minimized by Alt-TABing through already opened programs.)

Find RigWatch, click.

Reviewing the (right-click) Properties of the shortcut indicates where the software is located on disk.

The RigWatch main screen will fill the entire display, e.g.

Source Code for SLB to RW

Local copy

• C:\Users\daq\Documents\WPS to WITS - SLB to Rigwatch\VIs 2015\
  Double-click on SLB Winch Reader.lvproj to launch the LabVIEW 2020 development environment.
• The operational executable when built is placed here
  C:\Users\daq\Documents\WPS to WITS - SLB to Rigwatch\SLB2RW.exe (with a few other files).

Network copy

• U: or \\CLEVELAND\VOL2,  then \2-Engineering\2 RIS_RigWatch\RIS SOFTWARE\SLB to RW Software\
SLB2RW-2021-CODE
• A copy of the executable is stored in the same location: SLB2RW-2021-EXE

Theory of Operation - the Read Depth Loop

The code reads a binary data stream from the serial port, finds the WPD packets, then extracts the interesting fields from them. The WPD packets are identified by transmission pauses before and after. Complete packets are 54 bytes long; packets which do not meet this gross integrity check are thrown out. Since the protocol is time critical, it is crucial for the code to check the serial port at regular intervals. This is achieved by using a Timed Loop which has high timing reliability (much better than a "plain" software loop). In VI Info (Ctrl+I from the LabVIEW development environment), the VI's Execution property is set to the highest possible for the operating system and hardware in use. Historically "time critical" was specified; with current hardware and software "high priority" is sufficient. The loop period is tuned to 50 ms, 1/4 of the expected 200 ms pause, so the pause can be clearly identified.

Algorithm

A state machine is used which looks for these 3 conditions.

• If the state machine spends more than 10 seconds in any of these states it will timeout, raising a warning.
• If the timed loop takes greater than 100 ms or less than 10 ms per iteration, then synchronization with the WPD timing may have been lost. If this occurs, the state machine goes straight to the FindBreak state. Any partially received packet is discarded.
• When a new packet is successfully read, the "New Data" flag is set "True" for 50 ms. This signals other VIs to take action. The new data is written to a global.

** FindBreak ** - The starting state. Attempts to synchronize with the data stream.

• Wait for the pause in transmission which signals the gap between packets.
• Begin decoding a packet.
• Read and discard all bytes until one whole loop period (50 ms) expires without any bytes being received.
• Then processing is handed off to state FindStart.

**FindStart **

• Wait for bytes at the serial port.
• Every 50 ms observe if any bytes have been received.
• When bytes are received, records the start time.
• Processing is handed off to state Read.

** Read **

• Accumulate bytes read until one whole 50 ms period passes with no bytes received. This signals the end of the packet.
• If there are 54 bytes in the packet, process it to extract Depth, Tension, etc. (data)
• The data is placed in a queue.
• Processing is handed off to state FindBreak.

The code could be upset if illusory pauses in reception are seen due to delays between when characters come in to the serial port and when VISA's "Bytes at Port" function registers them. The code might then identify these as packet delimiting pauses.The 54-byt length check will almost always catch this, but there is a slim chance that 2 delays exactly 250 ms apart might create a bogus packet read. Once possible cause might be a large FIFO buffer (>54 bytes) on the serial hardware. It is recommended to turn off the FIFO on the WPD serial port (Device Manager > Serial Ports > COM4: right-click Properties, Advanced...). This change requires a restart of the host to take effect.

While this algorithm has run stably for years, it is tuned to the rate at which the Schlumberger hardware presents data. If Schlumberger equipment changes, this code will likely need to change.

Recapitulation of the Schlumberger WPD protocol specification

Depth data is transmitted from Schlumberger to our system over an RS422 serial line using the WPD protocol. The protocol is documented in Schlumberger's SSD Maintenance Manual, Appendix C. This is an old standard. The version in use on the JR is slightly different than what is documented. A summary specification of the JR WPD protocol variant is as follows.

Data packets are

• 54 bytes long
• transmitted 4 times per second at 19200 baud, no parity, 8 data bits
• the packets are delimited by a pause in transmission of ~200 ms
  "This timing critical protocol is a real pain to decode reliably."

The interesting parts of the data packet are

• Byte 0 - Flags. Bit 5 is units: 0=feet, 1=meters. JR usage has always been in feet.
• Bytes 3, 4, 5 - Depth. 24-bit 2's complement number. Specified in 0.1-inch units or an unspecified fraction of meters.
  • Byte 3 is LSB.
  • Byte 5 is MSB.
• Bytes 7, 8 - Speed. 16-bit unsigned integer. Units of ft/hr or m/hr, depending on byte 0.
• Bytes 12, 13 - Tension. 16-bit unsigned integer. Unit of pounds.

Software Dependencies

SLB to RW

SLB2RW is a compiled, 64-bit, LabVIEW 2020 executable. It is dependent on the National Instruments (NI) Serial drivers to communicate with the NI RS485 to USB device established at COM4.

Troubleshooting

Normal operational state

Windows Device Manager normally shows these devices. This view was captured with "View > Show hidden devices" checked.

These are the device configurations as of this writing and implementation. Note that a different driver supports each serial port established.

COM4

COM3

COM1

If there is a change in USB-to-serial equipment, drivers must be changed. If the drivers are changed, the designated COM#'s will too.

• Be sure to find and apply the current USB-to-serial driver for the device.
• Modern Windows (10 and above) driver Properties present an Advanced... button in their interfaces.
  • Typically it presents FIFO queue configuration options AND a field to assign the COM#.
  • Recommend changing the COM# to those specified at the beginning of this document
    OR recompile SLB2RW to reflect the new ports, revise this document, and retrain both crews.
  • If hardware breaks--do what you gotta do.

If the NI RS485 to USB device is unplugged

The Windows Device Manager will disable the serial driver (should still be visible via when View > Show hidden devices" is selected)Showwill be disabled, telemetry to RigWatch will stop. Best-case, it should suffice to plug the cable back in and continue on. It may be sufficient to plug the cable back in and restart the computer. Worst-case requires reinstallation (repair) of the NI-Serial