Omron Q2A Series Technical Manual

6.2 Modbus Communications
216 SIEPYEUOQ2A01A AC Drive Q2A Technical Manual
1. De-energize the drive then connect the communications cable to the PLC and the drive. The drive uses
terminal TB4 for Modbus communications.
A - Terminal AC: Signal ground
B - Terminal RS485+:
Communication input/output (+)
C - Terminal RS485-: Communication
input/output (-)
Figure 6.2 Communications Cable Connection Terminal (TB4)
Note:
Isolate the communications wiring from the main circuit wiring and other high-power wiring Use shielded wires for the
communications wiring and connect cable sheaths to the ground terminal of the drive. Incorrect wiring procedures could
cause drive malfunction because of electrical interference.
2. Install the termination resistor on the network termination slave drive. Set the DIP switch S2 to the ON
position to enable the termination resistor on the drive.
3. Energize the drive.
4. Use the drive keypad to set the necessary communications parameters H5-01 to H5-12.
• H5-01 [Mbus Address]
• H5-02 [Mbus BaudRate]
• H5-03 [Mbus Parity]
• H5-04 [Mbus Error Stop]
• H5-05 [Mbus Fault Detection Selection]
• H5-06 [Mbus Tx Wait Time]
• H5-09 [Mbus CE Detect Time]
• H5-10 [Mbus 0025H Unit Sel]
• H5-11 [Mbus ENTER Command Mode]
• H5-12 [Mbus Run Command Method Sel]
5. De-energize the drive and wait for the keypad display to turn off.
6. Energize the drive.
The drive is prepared to start communication with the PLC.
■ Set the Termination Resistor
You must enable the termination resistor on the slave terminal of the drive to use Modbus communications. Use
DIP switch S2 on the terminal block to enable and disable the built-in termination resistor. The following figure
shows an example of how to set DIP switch S2.
Figure 6.3 Modbus Communication Terminal and DIP Switch S2
Use the tip of a tweezers or a jig with a tip width of 0.8 mm (0.03 in.) to set the DIP switch. When you install the
drive in the terminal of the communication line, set DIP switch S2 to ON. Set DIP switch S2 to OFF on all other
drives.
■ Wiring Diagram for More than One Drive
The following figure shows how to wire more than one connected drive with using Modbus communications.

Omron Q2A Series Specifications

General

Brand	Omron
Model	Q2A Series
Category	Controller
Language	English