Four Channel Ultrasonic Positioning Device

Application Ultrasonic Tracking and Guidance Systems Object Orientation and Position Machinery and Automation Spatial Position Feedback Features Range up to 16m Max. Resolution 0.7mm Compensation for environmental noise HX944 4 Channel Ultrasonic Positioning Device The HX944 is a 4 positioning channel device. It can be configured as a pilot or beacons and has separate transmission and reception. If this device is set up as pilot it outputs 4 distances to each beacon. When set up as beacons, it behaves as 4 wired standard hexamite beacons. The HX944 can be ganged up with more HX944 devices to form a very large positioning array. The device comes with open wires, these can be extended to a needed length. Lengths shorter than 10m per sensor don't cause a significant performance degradation. It is up to the user how much performance degradation is acceptable as a trade-off for distance between sensors. The transmission and reception channels can be connected together when a single transceiver is used. This device will work with all 40khz transceivers and sensors sold by hexamite. Size: 1" x 2.8" x 2.8" (30 x 80 x 150 mm)

	HX944 Positioning Device
Compatible sensors are HE240TR, HE240TXRX, HE240TR, HE240TXRX, HE240STR, HE240STXRX

Wire Function

The HE944M has four wires connecting it to network and power. Two wires Red and Black provide the unit with power, two wires Green and Yellow facilitate communication with the HE944M. An auxiliary Blue wire is provided for testing purposes only.

Wire color	Wire function
Red/Orange	Power Input
Green	Ground/Common/Return
Yellow	RS485 Positive
Black	RS485 Negative
White	Synchronization
Blue	Test/Mode

White Wire: Synchronization Input

The device will synchronize on the rising edges of the input signal. If the device is configured as master this pin outputs the synchronization signal.

Electrical Specification
Parameter	Value	Units
Voltage Supply	7 - 16	Volts
Max Current consumption	20	mA
Sonic Transmission	40	Khz
Transmission Level	115	DB

The illustration below shows how HE944M positioning devices may be connected to a RS485 network. The wires connecting the devices can be up to 10 miles long. The network is plugged into the serial port of the central computer through a RS485 to RS232 converter, these are commercially available. Hexamite supplies the HE485DC designed to work for this type of network only.

CAUTION when using SEALED SENSORS

If the HE240STR or the HE240STX is being used to transmit the sonic wave, the voltage V supplied to the sensor must not go higher than 42V peak to peak for sustained periods. The illustration on the right shows a voltage divider used to protect the sensor. The voltage V becomes

V = V(he860) x R2 / (R2+R1)

The values for R1 and R2 should be selected so that the voltage V stays beneath 42V peak to peak.

The communication parameters for the HX944 version are

19200 baud, 8 bit, 1 stop bit, no parity. No Xon/Xoff handshaking

Important: The HC944 is extremely sensitive, while connected to a computer ungrounded switcher power supplies from laptops and desktop can disturb the HX944. In case of trouble make sure any device connected to the HX944 is well grounded. Laptops running on batteries do not disturb the unit while connected.

Wire color configuration for the HE860. Sensor wires cable color gray 2 conductors and a shield
RED	Sonar out: transmits sonar signal max 60Vp-p
YELLOW	Sonar in: receives sonar signal
SHIELD	Signal return (Ground)
When connecting a transceiver (single element for both transmission and reception) Red and Yellow can be connected together.

The illustration below shows how HX944 positioning devices may be connected to a RS485 network. The wires connecting the devices can be up to 10 miles long. The network is plugged into the serial port of the central computer through a RS485 to RS232 converter, these are commercially available. Hexamite supplies the HE485DC designed to work for this type of network only