SonTek/YSI Argonaut-XR Technical Manual - HydroScientific West

XYZ coordinate system
Argonaut Operation Manual Firmware Version 7.9 (May 1, 2001)
SonTek/YSI
When using the XYZ coordinate system, velocity measurements are stored using a right-handed
Cartesian coordinate system relative to the Argonaut. The positive X-axis is stamped into the
transducer head for easy reference.
For the Argonaut MD and XR, the definition of the XYZ coordinate system depends on the
hardware orientation setting (§5.1). For up-looking operation, the positive Z-axis is defined as
upwards along the axis of the sensor housing away from the transducer head. For down-looking
operation, the positive Z-axis is defined along the axis of the sensor housing from the top of the
transducer head into the housing. In both cases, the positive Z-axis is vertically up based on the
orientation of the system. The Y-axis is always defined from the X- and Z-axes to give a righthand
coordinate system.
Note that the alignment of the Y- and Z-axes with respect to the Argonaut housing changes
depending on the Argonaut orientation.
For the Argonaut SL, the positive Y-axis is defined along the axis of the sensor housing away
from the transducer head. For a typical deployment installation (with the cable from the sensor
housing going vertically up), this results in the standard configuration of the positive Z-axis as
vertically up (although the Argonaut SL measures velocity only in the XY plane).
BEAM coordinate system
When using the BEAM coordinate system, the Argonaut reports along beam velocity; positive
velocity is away from the Argonaut, negative is towards the Argonaut. The X-axis stamped on
the transducer head always points to beam number 1. If the Argonaut is placed on the floor with
the transducers looking up (with the user looking down at the system) the transducers are
numbered clockwise from #1.
6.5. Serial Communication Protocol
The Argonaut supports RS232 and RS422 serial communication protocols. Switching between
RS232 and RS422 changes the electrical interface and has no effect on the command interface of
the Argonaut. The default configuration is for RS232; this is the protocol used by the standard
serial ports on PC-compatible computers and is considered reliable for cable lengths to about
100 m.
RS422 communication uses differential voltage signals to increase immunity to external noise.
This allows operation over longer cables; RS422 is considered reliable for cable lengths to
1500 m. RS232 to RS422 converters are available commercially and allow an Argonaut using
RS422 communication to be connected to the RS232 serial port of a PC-compatible computer.
One supplier for this type of converter is shown below.
B&B Electronics Phone (815) 434-0846 Converter Part # 422COR
707 Payton Rd Fax (815) 434-7094 Power Supply Part # 422PS2
Ottawa, IL 61350 USA
The choice of communication protocol is set at the factory and cannot be changed by the user.
Contact SonTek directly if you have questions about the required serial communication protocol.
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