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Supply Current (Operating, 22C ambient)
|Acceleration Limit (for internal sensor)||± 50000||G|
Note: A lower power variant of the T7 is available on special order. Contact customer service for more information.
|Case Material||Glass filled polycarbonate|
|Weight||1.2 oz (34 g) nom.|
|Number of T7s in network||64|
|Cable length to furthest T7 in network (excluding stubs)||700||feet|
|Individual stub length||16||feet|
|Total length of all stubs||250||feet|
Note: The CAN version is designed to be used with the CANA-232/CANA-485 CAN to serial port adapter
|Number of T7s on bus||1|
|Maximum total cable length||100||feet|
Note: The T7 can drive 100 ft. of cable. Some PC's have limited drive on the RS232 bus which will limit the maximum cable length to less than 100 ft.
|Number of T7s on bus||32|
|Maximum total cable length||1000||feet|
1) Uses RS485 two wire network
2) Uses "fail-safe" drivers so bias resistors are not required
3) In most applications, the RS485 network does not need termination at 9600 bps with less than 1000 feet of cable. If termination is used, the RS485 network should be terminated with a 120-150 ohm resistor between BUS+ and BUS- at the source and at the last T7-1-485/T7-1-MOD4 on the network. US Digital terminating CAN cables (CA-CM-PS-CFTR) may be used at the last T7 on the bus to terminate it.
For a given network size, a minimum T7-1-485/T7-1-MOD4 power supply voltage is needed to ensure that the last T7 on the network is powered by at least 5.5V. The minimum power supply voltage can be calculated based on the number of networked T7s, the cable resistance/configuration and the current consumption of each T7 as a function of voltage. The following tables show the recommended minimum power supply voltage as a function of cable length and number of T7s for several common network wiring schemes. The tables assume that US Digital CAN cables with a resistance of 3.3 ohms per hundred feet (#22 AWG) for the two power lines are used. USD CAN cables have a twisted pair for the data wires and can be used for both CAN and RS485 versions. The following data is for room temperature (22C) operation. Please contact customer service for other possible network configurations.
Recommended minimum power supply voltage for T7s equally spaced on a total cable length, L. Stub length from T-adapter to a T7 is 6 feet.
|Number of T7's||Nominal supply current||Total cable length, L (T7's equally spaced)|
|100 ft||200 ft||300 ft||400 ft||500 ft||600 ft||700 ft||800|
Recommended minimum power supply voltage for T7s spaced 9 feet apart after an initial leader cable length, L. Stub length from T-adapter to a T7 is 6 feet.
|Number of T7's||Nominal supply current||Leader length, L (T7's spaced 9 ft. apart after leader)|
|100 ft||200 ft||300 ft||400 ft||500 ft||600 ft||
|Axis 2 Relative Angular Error||±0.1||Angular Degrees||0°C to 70°C, on-axis|
|Damping Time, milliseconds||Standard Deviation (σ)|
of Angle Noise, degrees
|95% confidence interval
(± 2σ), degrees
Note: T7 shown with factory default configuration.
The T7 uses a FIR (Finite Impulse Response) digital filter to provide electronic damping of the angle readings. The digital filter's impulse response has a triangular weighting that decays linearly to zero. The damping time is user programmable from 2 milliseconds to 5000 milliseconds. Since the sensor bandwidth is 8 Hz, damping times below 125 milliseconds do not provide any faster response. Increasing the damping time will average more samples together to form the reported angle. This will reduce noise in the output but increase the response time.
An inclinometer network assembled with the USD-CAN, RS232 or RS485 version of the T7 is shown below.
US Digital sells all the cables and connectors needed to wire a T7 network. The T7 uses the same connector for all interface versions.
Regardless of the interface option, a host PC, PLC or microcontroller communicates with a network of T7s by sending/receiving simple serial port commands over the RS232 or RS485 bus. In the case of the USD-CAN version, the CAN adapter serves as a command translator between a standard RS232/RS485 port and the USD-CAN bus used by the T7. The CAN adapter translates serial port command to the USD-CAN protocol and handles all network functions (access, error correction, etc.) to access the T7. Conversely, the CAN adapter also translates the reply from the T7 and sends the data to the host on the serial port. The CAN adapter frees the user from a complicated network interface on the host side. Note that the CAN adapter is not needed for the RS232/RS485 version of the T7. A host can communicate directly to these versions of the T7.
For more information on wiring the T7-1-CAN, see the CANA-232/CANA-485 Datasheet.
T7-1-232, T7-1-485, or T7-1-CAN Addressing
Each T7 on the network must be assigned a unique address from 1 to 100 or 127 (decimal). Address assignment is optional for the RS232 version. All T7s are shipped with a default address of 127. Address 126 is a special broadcast address - all T7s will listen and respond to commands sent to this address. To assign an address to a T7 unit, connect one T7 to a PC's serial port - either directly if using the RS232 version or through the CAN adapter for the CAN version. The address can be set using the the included PC based "T7 Demo" software . Alternately, a host computer can send the "Set Address" serial port command to the T7. This procedure only needs to be done once for each T7 since the address is stored in non-volatile flash memory.
T7-1-MOD2, T7-1-MOD4 Addressing
Each T7 on the network must be assigned a unique address from 1 to 100 (decimal). All T7s are shipped with a default address of 127. Address 0 is the Modbus broadcast address. To assign an address to a T7 unit, connect one T7 to a PC's serial port (an adapter is needed for the RS485 version). The address can be set using the the included PC based "T7 Demo" software. Alternately, a host computer can send a special "Set Address" command to the T7. This procedure only needs to be done once for each T7 since the address is stored in non-volatile flash memory.
|4||CANH / TXD / BUS+|
|5||CANL / RXD / BUS-|
All T7 units ship from US Digital with a default configuration. Configuration parameters are stored in non-volatile flash memory and can be easily changed by the user. The specifications are shown below. However, in larger quantities, special orders may be placed where the units can be preconfigured with any of the available settings noted in the T7 Communication User Guide or T7 Modbus Communication User Guide. Please contact customer service for special orders.
The T7 is now IP68 rated. For more details, download the T7 IP68 Certification.
The T7 is a solid state absolute inclinometer that senses tilt angles over a full 360° range in a single axis. A multi-axis version is planned for the future. The T7 is sealed against dust (IP68 rated) for operation in dirty environments. The T7 incorporates a number of breakthroughs to create a new type of inclinometer that is rugged, compact, fast, flexible and easy to use.
The T7 is available in several interface and protocol options. The physical interface can be RS232, RS485 or US Digital's CAN (Controller Area Network). The protocol can be either US Digital's serial protocol or Modbus RTU. The RS232 version supports a single T7 with up to 100 ft of cable. For users that need longer cable lengths or multiple T7s on a single bus, the RS485 or US Digital CAN (Controller Area Network) version can be used. The USD-CAN protocol allows a network of up to sixty-four T7s to be connected to a single host. Power for each T7 is supplied over the CAN network cable. The host accesses the USD-CAN T7s through US Digital's low cost CANA-232/CANA-485 adapter module. This module allows the host to access each T7 on the network using simple, easy serial port commands, just like the RS232 version. The RS485 version supports up to 32 T7s on the bus.
The Modbus RTU version is suitable for users that require an industry standard, open protocol. The host may access each T7 on the bus using standard Modbus read/write register function codes.
The T7 calculates tilt angle (inclination) by sensing the acceleration from solid state accelerometers integrated into a monolithic chip. Gravity, centrifugal forces, and linear speed changes are all forms of acceleration. The T7 will report the mathematically calculated tilt angle based on all sensed acceleration(s).
The serial port interface provides an efficient way to read and write data to a network of T7s. All configurations and parameters are stored in nonvolatile memory. A Windows demo application is provided for displaying the angles and temperature as well as setting operating modes, orientation, zero position, damping / averaging time, direction, and more for every T7 on the network. In addition, a Windows DLL gives the user a set of simple functions to read and write data to a network of T7s.
Typical applications include heavy construction equipment, dredging machinery, mining equipment, solar tracking and warehouse automation.