System Layout Diagram (Simplified & Color-Coded)
Proper TriVibe Layout:
- A Modbus Master which has properly designed RS-485 (TIA-485(-A)/EIA-485)
ports with built-in pullup and pulldown resistors enabled to enforce the RS485
(TIA-485(-A)/EIA-485) electrical standard. - A single field cable bus trunk for each RS-485 (TIA-485(-A)/EIA-485) port
available from the Modbus Master. - Each T-Port connection terminal allows a TriVibe Tri-Axial Vibration Sensor to
drop off the field cable bus trunk by way of the integral sensor cable. - On each available RS485 (TIA-485(-A)/EIA-485) port, only the last/furthest T-Port
connection terminal should have a jumper installed, thereby enabling the 120Ω
terminating resistor. - As long as you do not plan to expand with more TriVibe Tri-Axial Vibration
Sensors on a particular field cable bus trunk, It is permissible to use the last set
of terminals of the last/furthest T-Port to connect a TriVibe by way of the integral
sensor cable. - Field cable which adheres to RS-485 (TIA-485(-A)/EIA-485) specification and
Machine Saver's recommended characteristics. - Total length of field cable bus trunk should not exceed 2800 feet (855 meters)
for Modbus Masters communicating at a baudrate of 115,200 bit/s. - 24 - 36 VDC should be verified available to power each TriVibe Tri-Axial Vibration
Sensor at each T-Port connection terminal which includes the T-Port which is
furthest/last on the field cable bus trunk from the Modbus Master.
Improper TriVibe Layout:
- A Modbus Master which has IMPROPERLY designed RS-485 (TIA-485(-A)/EIA-485)
ports. Missing (or disabled) built-in pullup and pulldown resistors leaving the
bias-voltage at an unknown level. - A field cable bus trunk which uses a T-Port connection terminal to attempt to
split the field cable bus trunk, thereby violating the RS-485 (TIA-485(-A)/EIA-485)
electrical communication standard. - The above issue also results in 2 furthest T-Port connection terminals to be
identified, if you attempt this and see there are 2 possible places to install
a jumper AND/OR if you have more than 1 jumper per RS-485 port re-evaluate your
layout. The layout cannot remain in these conditions and function appropriately. - Field cable adheres to RS-485 (TIA-485(-A)/EIA-485) specification and
Machine Saver's recommended field wire chart characteristics. - Total length of field cable bus trunk MUST NOT EXCCED 2800 feet
(855 meters) for Modbus Masters communicating at a baudrate of 115,200
bit/s. - Allowing the voltage supplied to any TriVibe Tri-Axial Vibration Sensor at any
T-Port connection terminal to drop below 24 - 36 VDC which includes the
furthest T-Port from the Modbus Master. - Allowing the current supplied to any TriVibe Tri-Axial Vibration Sensor at any
T-Port connection terminal to drop below 50 milliamps.
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