Bardac drives P2 Series, Manual

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Version 3.01
| P2 Series User Guide |
61 www.bardac.com
9
Serial Communications
9. Serial Communications
9.1. RJ45 Connector Pin Assignment
The P2 drive has an RJ45 connector on the front of the control panel. This connector allows the user to set up a drive network via a
wired connection. The connector contains multiple interfaces for different communication protocols:
 Optibus Protocol - Used for PC and peripheral connection only
 Modbus RTU
 CANBus
The Optibus connection is always
available, and can be used simultaneously
with other interfaces, however only one
other interface may be used, e.g. If
Modbus RTU is in use, CAN is disabled. If
a Fieldbus Option Module (E.g. Profibus)
is inserted into the drive, both Modbus and
CAN are disabled.
The electrical signal arrangement of the
RJ45 connector is shown as follows:
1
CAN-
2
CAN+
3
0 Volt
4
Optibus / Remote Keypad / PC Connection
5
Optibus / Remote Keypad / PC Conn
6
+24 Volt Remote Keypad Power Supply
7
-RS485 (Modbus RTU)
8
+RS485 (Modbus RTU)
9.2. Modbus RTU Communications
9.2.1. Modbus Telegram Structure
The P2 drive supports Master / Slave Modbus RTU communications, using the 03 Read Holding Registers and 06 Write Single Holding
Register commands. Many Master devices treat the first Register address as Register 0; therefore it may be necessary to convert the
Register Numbers detail in section 0 by subtracting 1 to obtain the correct Register address. The telegram structure is as follows:
Command 03 – Read Holding Registers
Master Telegram Length Slave Response Length
Slave Address 1 Byte Slave Address 1 Byte
Function Code (03) 1 Byte Function Code (03) 1 Byte
1st Register Address 2 Bytes Byte Count 1 Byte
No. Of Registers 2 Bytes 1st Register Value 2 Bytes
CRC Checksum 2 Bytes 2nd Register Value 2 Bytes
Etc...
CRC Checksum
2 Bytes
Command 06 – Write Single Holding Register
Master Telegram Length Slave Response Length
Slave Address 1 Byte Slave Address 1 Byte
Function Code (06) 1 Byte Function Code (06) 1 Byte
Register Address 2 Bytes Register Address 2 Bytes
Value 2 Bytes Register Value 2 Bytes
CRC Checksum 2 Bytes CRC Checksum 2 Bytes
9.2.2. Modbus Control & Monitoring Registers
The following is a list of accessible Modbus Registers available in the P2 drive.
 When Modbus RTU is configured as the Fieldbus option, all of the listed registers can be accessed.
 Registers 1 and 2 can be used to control the drive providing that Modbus RTU is selected as the primary command source (P1-12
= 4) and no Fieldbus Option Module is installed in the drive Option Slot.
 Register 3 can be used to control the output torque level providing that:
o The drive is operating in Vector Speed or Vector Torque motor control modes (P4-01 = 1 or 2).
o The torque controller reference / limit is set for ‘Fieldbus’ (P4-06 = 3).
 Register 4 can be used to control the acceleration and deceleration rate of the drive providing that Fieldbus Ramp Control is
enabled (P5-07 = 1).
 Registers 6 to 24 can be read regardless of the setting of P1-12.