HIT-NOT DDAC-PDS-SXL-C Magnetic Field SXL Generator User Manual
- June 6, 2024
- HIT-NOT
Table of Contents
HIT-NOT DDAC-PDS-SXL-C Magnetic Field SXL Generator
Huntsville, AL 35806
1.800.489.6915
- US7,420,471;
- US8,169,335;
- US8,232,888;
- US5,939,986;
- US6,810,353;
- AU2005289704;
- ZA2007/02919;
- ZA2008/02673;
- ZA2010/06816,
- ZA2010/09068 Patent Pending
Overview
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The Magnetic Field SXL Generator (MFG), model DDAC-PDS-SXL-C, is part of a complete HIT-NOT® Proximity Detection System from Frederick Energy Products that installs on lift trucks or other moving vehicles and creates pulsing magnetic fields sensed by other devices. The other devices detect the magnetic fields and determine when they are too close to the lift truck.
For example, a pedestrian wearing a Personal Alarm Device (PAD), model DDAC- PAD, can detect the fields from MFGs and provide warnings to the pedestrian and the truck operator to alert them both that the pedestrian is too close to the truck and is in a dangerous situation. The MFG also includes an internal Collision Avoidance Module (CAM) that detects magnetic fields from MFGs on other moving trucks to provide warnings when there is a risk of collision with another truck. The operation of the CAM is similar to that of a PAD, but a different -
LED/Sounder pattern is used to differentiate between a truck in a magnetic field and a pedestrian in a magnetic field.
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The MFG also includes a Bluetooth Module that can provide proximity-event data to remote users. Proximity-event data are stored in MFG memory and the Bluetooth Module transmits the proximity events to a Bluetooth Relay, when the MFG is near a relay. The relay then sends the data to the remote user via Cloud Services.
Theory of Operation
The primary functions of the MFG are:
- To generate a 73 kHz field around a truck to act as a protection zone for collision avoidance between trucks and for the protection of pedestrians.
- To receive a 916.48 MHz RF signal from a Personal Alarm Device (PAD) and/or a Collision Avoidance Module (CAM).
- To sense magnetic fields emitted by MFGs on other lift trucks and transmit a 916.48 MHz signal from the CAM to a Magnetic Field Generator in the other truck.
- To collect and store proximity events that can be transmitted by an internal Bluetooth Module to a Bluetooth Relay for subsequent transmission to remote users via Cloud Services.
The MFG has an internal 73 kHz generator and a wire-wrapped ferrite radiator that creates a field to serve as a cautionary zone around the lift truck. It also contains a Collision Avoidance Module (CAM) that detects magnetic fields emitted by MFGs from another truck.
When a PAD or another lift truck with CAM is in close proximity to the MFG, the PAD or CAM will detect the 73 kHz magnetic field from the MFG and analyze its field strength. If the 73 kHz field strength received by the PAD or CAM is above a certain threshold, indicating the distance to the PAD or CAM is close enough to signify a Warning condition, then the PAD or CAM will reply to the MFG with a 916.48 MHz transmission.
The MFG has its 916.48 MHz transceiver ON when it is generating the 73 kHz
magnetic field and is “listening” to receive any 916.48 MHz transmissions from
a PAD or CAM. If the MFG receives an indication that a Warning or Danger
condition exists, it will turn ON a connected Warning Module with LED and
sounder.
The Bluetooth Module is a fully certified module (FCC ID: T9JRN4020) mounted
on the MFG printed circuit board. It transfers proximity-event data
collected/saved by the MFG to Bluetooth Relay(s) installed at selected
locations in a facility for subsequent transmittal to remote users via Cloud
Servers.
Operating Frequency
The MFG creates pulsing magnetic fields on a frequency of 73 kHz and receives RF signals on a frequency of 916.48 MHz. The transceiver in the MFG transmits signals from its own Collision Avoidance Module on a frequency of 916.48MHz.
The CAM detects magnetic fields from MFGs on other trucks on a frequency of 73kHz, but the CAM is programmed to not recognize the 73 kHz magnetic field from its own MFG. The Bluetooth Module operates with frequency range of 2.4 – 2.48 GHz. To comply with nerve stimulation guidelines, it is recommended that personnel do not come within 7.8 in (20 cm) of the MFG while in operation.
FCC/IC Information
The FCC ID for the MFG is QUI-DDAC-PDS-SXL-C and complies with Part 15 of the FCC Rules. Operation is subject to the following conditions:
- This device may not cause harmful interference.
- This device must accept any interference received including interference that may cause undesired operation.
Any intentional or unintentional changes or modifications to the configuration
of the Personal Alarm Device not expressly approved by Frederick Energy
Products LLC could void the user’s authority to operate the equipment.
Note: This equipment has been tested and found to comply with the limits
for a Class B digital device, pursuant to Part 15 of the FCC Rules. These
limits are designed to provide reasonable protection against harmful
interference in a residential installation. This equipment generates uses and
can radiate radio frequency energy and, if not installed and used in
accordance with the instructions, may cause harmful interference to radio
communications. However, there is not guarantee that interference will not
occur in a particular installation. If this equipment does cause harmful
interference to radio or television reception, which can be determined by
turning the equipment off and on, the user is encouraged to try to correct the
interference by one or more of the following measures:
- Reorient or relocate the receiving antenna.
- Increase the separation between the equipment and receiver.
- Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.
- Consult the dealer or an experienced radio/technician for help.
The required notices are specified in the RSS documents (including RSS-Gen)
applicable to the equipment model. These notices are required to be shown in a
conspicuous location in the user manual for the equipment, or to be displayed
on the equipment model. If more than one notice is required, the equipment
model(s) to which each notice pertains should be identified. Suppliers of
radio apparatus shall provide notices and user information in both English and
French.
This device complies with Industry Canada license-exempt RSS-standards(s).
Operation is subject to the following two conditions:
- this device may not cause interference, and
- this device must accept any interference, including interference that may cause undesired operation of the device.
Operation
Installation Information
The MFG is mounted on a vehicle or piece of machinery. It is ideally mounted
on top of the vehicle on a near flat surface. It also should be mounted with
the long dimension of the MFG parallel to the direction of travel. This
orientation takes advantage of the inherently oval shape of the MFG magnetic
field to maximize the field in the direction of travel and minimize the field
at the sides. (see figure at right)
Metal near the MFG may impact performance by reducing the field size;
particularly metal near the ends of the MFG housing. Thus, the MFG should not
be installed such that either end of the housing is within approximately 4 in
(100 mm) of a steel truck component.
The internal layout of the MFG components is designed/adjusted to be mounted
with the MFG base connected directly to steel. However, if the structure that
the MFG is mounted on is not steel, then factory setting for magnetic field
size may be altered.
If this is the case, contact the HIT-NOT Dealer about a readjustment of the 73
kHz tuning. Also CAM detection can be affected by other close-by components on
the truck that emit electromagnetic interference (EMI). These components
include a Xenon strobe light or a cab silencer if installed within 21 inches
of the MFG. After installing the MFG on the truck, performance of the unit
should be verified by operation and test.
Inoperability Warning
The MFG CAM operation may experience erratic responses when in very close
proximity to some electronic devices. Electrical devices may transmit an
electrical field and noise that may cause interference with the CAM. A safe
guideline is to keep the MFG at least 4in or 100mm away from any electrical
devices included but not limited to methane monitor, radio, mobile phone, GPS,
PDA, battery charger and laptop computers.
Charging
The MFG does not require charging. It is directly powered when the ignition of
the truck is turned on.
Alerts
Magnetic Field Generators are designed to automatically adjust and maintain
the original magnetic field size. If the truck supply voltage changes or
changes occur resulting in a reduction of field sizes, the system will
automatically adjust as much as 5% to ensure that the field size remains where
it was initially set. If the processor senses a significant power reduction,
the alarm may sound for a period of time. When the sounder is activated, power
must be cycled to restore normal operation. If the problem persists, then
service is required.
Maintenance
The MFG should be regularly cleaned to reduce buildup of dust and dirt. The
user should check to see if the LEDs are working before using the system each
day. There is a blue power-LED visible on the MFG housing. There also is an
LED that indicates the alarm status of the MFG and works in tandem with a
Warning Module connected to the MFG
Adjustments
Magnetic field size and sounder volume of the Warning Module Volume are
adjustments which can be made by the user. These adjustments are made remotely
using a Range Adjust Tool, Model No. HN-RANADJ, described in a User’s Manual
specifically for the Range Adjust Tool.
There are other available functional options that are manually selected via
switches on the printed circuit board. These options are configured by the
manufacturer during assembly but may also be changed during generator
installation. Access to the switches is gained by removing the red plug in the
side of the generator housing.
( Note: do not remove the entire side of the housing to change switch
settings. Removing the side would break the sealant applied to seal the
housing at assembly to prevent moisture intrusion.)
Options are:
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Collision Avoidance Module Alarm Timing – This option, set using Switch “USER20”, selects whether or when a CAM alert “times out” and whether re-alerts occur. The available selections are:
➢ Continuous – Alarms as long as the truck is in the magnetic field of another MFG. Set when Sw1 is OFF and Sw2 is ON.
➢ Two Second Alarm, no Re-alert. Set when Sw1 is ON and Sw2 is OFF.
➢ Two Second Alarm, Re-alert after 30 seconds. Set when Sw1 is ON and Sw2 is ON.
➢ Two Second Alarm, Re-alert after 60 seconds. Set when Sw1 is OFF and Sw2 is OFF. -
Dual Volume Tone for Warning Module Sounder – This option determines whether the sounder in the HIT-NOT® Warning Module is at constant volume level or whether the sound volume starts at high level but is reduced to a lower level after a short time. The intent of this option is to first obtain the operator’s attention and then reduce the volume to a less intrusive level. Switch “Sw1” in the Switch “USER10” determines which setting will be applied. When “Sw1” ON, the volume level remains constant throughout. When “Sw1” is OFF the dual volume level is set.
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Collision Avoidance Module Disable – Disables the CAM from providing responses to magnetic fields from other trucks with MFGs installed. With switch “Sw2” in Switch “USER10” set to OFF the CAM is fully functional and set to ON the CAM is disabled. These adjustments must be made ONLY by an approved person.
Interferences
The Magnetic Field Generator may receive false triggering (generate an alarm)
signals from some RF-based devices including high-power radios and cell
phones. Such devices will need to be moved further away from the generator. If
the devices may not be moved, then the path may need to be marked to indicate
areas of interference of the system. If possible the route may need to be
changed.
Generator Specifications
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Part Number:
DDAC-PDS-SXL-C -
Size:
13” x 6” x 4.5” (Depth is 4.5” at widest point and 2”at the narrowest) -
Weight:
7.2 lbs./ 3.2 kg -
Input Voltage:
24 VDC (nominal) -
Magnetic Field Frequency:
73 kHz pulsing AC field. Magnetic field pulses occur approx. 3% of the time. -
Maximum Current Draw:
Less than 5A. It is not a constant draw with a magnetic field pulsing at 3% of the time. Current draw between pulses is very low and the overall current draw is low. -
Transceiver:
Microchip Model MRF89XA -
Transceiver Transmit/Receive Frequency:
916.48 MHz -
Transmitter Power:
0.001 W (typical) -
Bluetooth Module:
Microchip Model RN4020 [FCC ID: T9JRN4020] -
Bluetooth Module Transmit Frequency:
2.402 – 2.480 GHz -
Operating Temperature Range:
-30°C to + 55°C; -22°F to 131°F
Safety Consideration
The driver and pedestrian should not be in close proximity while the truck is
in gear. The driver must turn OFF the truck while a pedestrian is standing
next to the truck.
Revision History
Version 1.0 – May 6, 2021
Original Release. No revision history.
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