system
A set of hardware devices and their associated software capable of performing the functions of information processing and device control without significant dependence on other equipment.
tap
A passive electrical device that joins segments of the trunk cable or terminates the trunk cable at its two end sites. It also provides a connection for the drop cable to the node device at the tap site. See terminator.
terminator
A resistive load placed at the end of a cable to prevent data signals from reflecting back into the data path. The signals are terminated with the same impedance as the characteristic impedance of cable system. On Modbus Plus each tap contains a terminating resistor with two jumpers. The termination is effective when the jumpers are installed. The tap at each of the two ends of the cable section has its terminating jumpers installed. The tap at each inline point has them removed. See section.
token
In data transmission a frame passed on a network that gives a networked device the current authority to transmit.
token bus
A network access method between two or more devices in which the procedure for sending data is based upon the passing of a token for access to the network. See token.
transaction
The complete and successful transfer of a message between networked devices.
trunk
The main element of the cable system that interconnects the network nodes. On Modbus Plus the trunk cable runs directly between pairs of taps.
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