In February 2011, Chetco Digital completed an install on the PACCAR Motor Yacht Alliance: a 130 foot luxury vessel with twin Cat mechanical diesels.  The vessel helm was retrofitted to remove all analog gauges and replace with digital video displays monitors driven by multiple PCs for navigation, sonar, and instrumentation.  The engine room gauges were mix of mechanical and analog, with no secondary panel.

Since a new helm was being outfitted with PC based displays, it was decided to use twin SeaGauge Remote Sensor Units in the engine room and send gauge data up to the helm PC over dual serial (RS232) links. The serial cables were small in diameter and capable of running up to 300 feet.  Once up at the helm PC, they were terminated with USB to Serial adapters for each interface with PC ports.

Alliance Engine Room

The PC was running a single copy of Chetco's vDash Instrumentation Software and a sonar display program. The captain wished  to use the Picture-In-Pictue (PIP) feature of the 19” screens to switch between ship-board video cameras, sonar system, and engine instrumentation – all on one monitor.

Alliance Dash (Chetco's vDash Software working in conjunction with Sonar, GPS, and Navigation)

The dual SeaGauge Remote Sensor Units we configured for a single engine with a separate unit for Port and Starboard.  Each unit was setup for a Tachometer, Engine Temp, and Oil Pressure, which utilized only 3 of the 16 functions. The remaining features are available for future expansion such as EGT (PYRO), voltage, and Tank monitoring.  Since it was desired to keep the existing mechanical gauge panel in the engine room, separate senders were added for the Tachometer (inductive flywheel pickup), temperature (VDO resistive 250F max) , and oil pressure (VDO resistive 80 PSI).

The ship engineer installed the additional senders in spare ports on the engine water cooler and oil pressure manifolds within 5 feet of the unit.  The Tachometer pickup was mounted on the bell housing to sense the teeth of the flywheel. The SeaGauge Remote Sensor Units were outfitted with 24V to 12V DC-DC converters to allow them to be run by a breaker in the engine room.

The only problem that occurred with the installation of the Remote Sensor Unit as one of the flywheel sensors failed to to pickup any pulses, initially. This was discovered when the vDash Instrumentation Software was being configured at port, and no reading was displaying for the starboard engine.  A trip back down to the engine room reviled the Green LED on the Tachometer terminal was not flashing, indicating something was wrong with the input.  A voltmeter on the terminal confirmed no reading (0V) when the other unit was showing (1.2V). After removing the sensor from the bell housing, it was discovered the magnetic tip was covered with metal debris from the thread hole which prevented operation. After cleaning off the tip and inserting back into the housing, the pulse LED did flash and the vDash S/W on the helm PC giving a uncalibrated reading.

vDash configuration on the helm PC consisted of setting up two windows for the Port and Starboard engines with display of Tachometer, Engine Temp, and Oil Pressure. Two separate copies or the vDash Project folder were created for each engine. Next, a copy of the vDash application was created in the program folder and renamed “vDash Starboard Engine”. The orginal copy was then renamed to “vDash Port Engine”. A short-cut to each program was placed in the Windows Start Menu so that two instances of the program could be run at the same time. Once the two instances were created, they could be directed to separate USB ports coming from each of the SeaGauge Remote Sensor Units. This the allowed both units to be displayed on same monitor.

After the separate projects were created, the actual screen layout was designed using vDash. This consisted first of selecting a desired theme. After first showing the Captain the “Classic White” theme, a preference was indicated for a darker background so the “Classic Black” theme was chosen. In order to fit both displays on the same monitor, the “G6” display size was selected since it allowed for creating two horizontal windows with a single row of gauges. Finally, the tachometer, engine temp, and oil pressure gauges were added to the windows.

The captain had a preference for the names applied to each gauge. This was easily accomplished by typing them in from the keyboard and then updating the units.

Calibration of the system consisted of adjusting the tachometer with engines at idle and at full open. Initial idle showed 4999 on the gauge while actual was 500. This was due to the inductive pickups counting the teeth of the flywheel and not actual revolutions. The vDash Options Screen has a place to enter the number of teeth which divides down the count. The entry was made for 150 teeth which brought the tach down to 600. The ship’s engineer went down to the engine room to radio up the readings for the analog panel and the teeth parameter changed to 155 which brought both gauges down to the desired 500. The engines were then brought up to 1200 and both meters tracked the same. Since the engines would never see more then 1200 RPMs, it was decided to increase the sample interval from 1 to 2 seconds to give better low end tach resolution. Increasing the sample interval required an equal decrease in display scale to achieve the same 500 RPM at idle. Thus, only a few simple adjustments were made to bring both tachometers on-line. The preloaded Temperature and Oil Pressure calibrations we verified to be accurate and required no adjustments.

The basic vDash setup and configuration was completed in only a few hours which the captain and engineer being able to participate in providing input on desired screen layouts and labeling. The longest part of the install was installing the additional senders and running the cable from the engine room to helm station.

While on the Alliance, the new SeaGauge G32N dedicated display panel was shown to the captain who quickly understood the value of having the ultra bright panel installed in the console to give full-time engine information similar to the PC system. After some discussion on how the new display could be added to the system to run in parallel with the PC based system, it was decide to purchase and install the display as well. Since serial data was already available to the PC within a few feet, it was possible to cascade the displays with out needing to run additional cable. The installation of the second panel will be the topic of the next blog entry.

Joe Burke
Chief Technology Officer
Chetco Digital Instruments, Inc.