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Shipping Information

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Additional Information

The Emerson UD75 is a Large Option Module CTNet Interface Card for the Unidrive, and is an add-on card for the UD70 Applications card. The CTNet Interface uses a green 5-pin terminal block and the 9-way D-type connectors are the RS323 and RS485 ports for the UD70. Bi-Phase S Signaling is used, which is non-phasic, so it does not matter which wire is linked to Net+ and Net-. The cable’s screen at every not on the network must be connected to the screen terminal (pin 3) on the CTNet terminal block. Keep the exposed section of the cable as short as possible when the screen is stripped back to connect the twisted pair to the CTNet terminals. On the CTNet PC Interface Adapter Card, there is no screen terminal. The screen should be cut and taped back to prevent it from coming into contact with any other surfaces. The terminal resistor on-board should not be connected.

Terminating resistors must be fitted on the network at both ends. If this is not done, the network may appear to work, but the noise immunity will become greatly diminished. The ending resistor value should be equal to the nominal characteristic impedance for the cable. The terminating resisters should normally be 78Ω if you choose to use a customized CTNet cable. Networks are capable of driving a max of 15 nodes of a max cable length of 300ft at 5 Mbits/Sec. The max cable length is increased to 600ft if the network data rate decreases to 2.5 Mbits/Sec., but the 15 node limit stays the same. To set the network node address, use the Unidrive parameter #20.01 and Mentor II parameter $14.05. Each node needs a unique network address between 1 and 255. In the case of an invalid address being set, the UD75 will go back to a default address of 1. Address changes only take effect after the Control Techniques UD75 has been reset. To reset the UD75 interface, set #MM.00 to 1070 and press the red RESET button the keypad. This will not reset the Unidrive, only the UD75.

All network nodes must be set to perform at the same data rate. This is set by programming the right code in #20.02 on the Unidrive. If the node data rate differs than the network, it may prevent the network from initializing properly. This rate can run from 5.0 Mbits/second (if the cable is 100 meters) to 312 Kbits/second (if the cable is 1200 meters). The cyclic data synchronization code is shown in the #20.03 on the Unidrive. If this feature is used, each node can transmit data to others when it receives the network token. Since this is a peer to peer system with no overall controller, one node has to be given the task of synchronizing the other nodes. This synchronization message is given at programmed intervals and transmits at the start of each cyclic data period. Two cyclic channels are available on CTNet - fast cyclic data and slow cyclic data. The fast data channel is transmitted every sync message cycle, the slow channel is done every nth cycle.


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