Installation manual

48
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 60. 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 "0V"
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 220 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.
The modbus protocol is sensitive to transitions on an idle line. In some cases it may be necessary to apply bias to
the trunk consisting of a pull-up resistor to RX TX and a pull-down resistor to RX/ TX/. Biasing is most important when
termination resistors are used. As an example, if the internal 220 ohm termination is connected at the last node on
the trunk, a 10K resistor from RX TX (pin 2) to +15 V (pin 4) and a 1 K resistor from RX/ TX/ (pin 7) to Isolated 0V
(pin 3) would provide good idle line bias. Only one node needs to provide bias, even with terminators at each end.
It is usually most convenient to provide bias at the connection to the Modbus master node.
Communication Converter Cables
The CT-Comms cable is an isolated RS-232 to RS-485 converter cable 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 CT-USB-Cable is an
isolated USB to RS-485 converter cable that may be used to connect one or more drives to a master device using
a USB port.
The +15 V supply (pin 4) and the 0 V connection (pin 3) are intended only to provide power to the isolators in the CT
converter cables and are not to be used for any other purpose.
The TX Enable signal (pin 6) and 0 V (pin 3) provide a transmit enable signal from each interconnected drive to the
CT converter 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 converter cable to communicate with all drives in the group.
The DDC-RJ45 cable provides drive to drive (daisy chain) connections between EP drives, including support for the
CT converter cable in a group of drives.
Pin Function
1 220 ohm Termination resistor to RX TX
2RX TX
3Isolated 0V
4 +15V (100 mA max)
5NC
6 TX Enable
7RX/ TX/
8 RX/ TX/ (If termination resistors are required, link to pin 1)
SHELL PE