Emerson 400518-01 - Manual (Page 49)

Installation 37
Safety Information Product Overview Installation Diagnostics
Options and
Accessories
Specification
Communications
Communications with the drive is provided through the RJ45 connectors located on the front of the drive. The two
RJ45 connectors are identical and are used to provide a way to daisy chain two or more drives together using the
DDC-RJ45 cable, see Figure 44. The Epsilon EP serial communication connector (serial port) as standard, supports
2 wire EIA485 communications. The RS-485 communications port is not isolated from drive electronics and the "0
V" pins are internally connected through a 10 Ohm resistor to PE. Interconnected drives should be within a zone of
equipotential bonding. Connection to a master device on the network, such as a MMI, SCADA, PLC, or PR can be
remote, but care should be taken to make sure the entire network operates within the +/-7 V common mode voltage
range of RS-485. Though the comm port is part of PELV circuits when properly installed, if the master device is
outside the zone of equipotential bonding the circuit needs to be isolated against direct contact. The minimal RS-485
network cable contains a shielded twisted pair for RX TX (pin 2) and /RX /TX (pin 7) with shield to the shell, though
a 0 V reference signal (pin 3) can improve immunity to ground differentials. See the following table for the connection
details for the RJ45 serial communication connector.
The provision for connection of the internal 120 ohm terminating resistor at pin 1 and pin 8 would rarely, if ever, be
needed unless data rates much higher than 19.2K are supported. Since a terminator connection is only made at the
end of a trunk, it is most conveniently accomplished by crimping a short link from pin 1 to pin 8 in a new RJ45
connector and plugging it into the second RJ45 port on the "last" drive. Cable conductors should not be connected
to these pins.
Communication Cables
The CT-Comms cable is an isolated RS-232 to RS-485 convertor that may be used to connect one or more EP drives
to a master device using a standard 9 pin D-sub RS-232 serial comms port. The +15 V supply at pin 4 and the 0 V
connection at pin 5 are intended only to provide power to the isolators in the CT-Comms cable and are not to be used
for any other purpose.
The TX Enable signal at pin 6 and 0 V at pin 3 provide a transmit enable signal from each interconnected drive to a
CT-Comms cable and are not to be used for any other purpose. They may be wired from drive to drive in a zone of
equipotential bonding to allow the CT-Comms cable to communicate with all drives in the group.
The DDC-RJ45 provides drive to drive (daisy chain) connections between EP drives, including support for the CT-
Comms cable in a group of drives.
Pin Function
1 120 ohm Termination resistor
2 RX TX
3 Isolated 0V
4 +15V (100 mA max)
5 Isolated 0V
6 TX Enable
7 RX/ TX/
8 RX/ TX/ (If termination resistors are required, link to pin 1)
SHELL PE