Performance Motion Devices CME N Series, User Manual

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36 ION/CME N-Series Digital Drive Developer Kit User Manual
2
Figure 2-4:
RS485 Signal
Connection
Diagram
RS485 is a master slave system. When connecting to a PC running Pro-Motion the PC functions as the master, and
each N-Series ION in the network functions as a slave.
Figure 2-4 shows the basic wiring scheme that is used for a full
duplex (four-wire) connection. Four wire is recommended over two-wire because it has higher reliability. Additional
details such as what wire type to use, wire shielding, twisting differential wire pairs, length of wire etc. will not be
detailed here but are important so a reference text on RS485 networks should be consulted.
For reliable communications the last unit on both sides of the network cable should provide termination. For most
systems 120 ohms of termination resistance is recommended. N-Series IONs provide user programmable internal
termination of 120 ohm.
For additional information on serial communication functions with N-Series IONs refer to the ION/CME N-Series
Digital Drive User Manual .
To prepare the PC to function as the RS485 master an RS422/485 USB adapter or RS485 card should be purchased
and installed. Follow the product directions to install the software drivers. If properly installed and visible to Windows,
Pro-Motion should recognize the RS485 port and be able to communicate with it automatically. For convenience the
following table lists a vendor and P/N for such an adaptor product:
2.2.6 Setting Up the ION for RS485
Communications
Each ION unit to be installed in the RS485 network needs to be programmed with network settings. If the IONs are
mounted on the DK interconnect board, these settings can be programmed using Pro-Motion communicating to the
ION via the 3-pin programming port.
Each successive ION will be programmed, powered down, and then the 3-pin cable is detached and attached to the
next unit to be programmed. After the final unit is programmed the 3-pin programming cable should be detached.
Vendor P/N Description
Advantech BB-USOPTL4 Isolated high retention USB to RS422/485
converter (USB cable included)
Host/Master
Port
DK Board J12
Host Serial Connector
TX+
TX-
RX+
RX-
GND
5 6 7 8 9
GND
RX+
RX-
TX-
TX+
ION #1
5 6 7 8 9
GND
RX+
RX-
TX-
TX+
ION #2
5 6 7 8 9
GND
RX+
RX-
TX-
TX+
ION #3
DK Board J12
Host Serial Connector
DK Board J12
Host Serial Connector