Optidrive HVAC User Guide V2.00
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10.2.2.
Modbus Control & Monitoring Registers
The following is a list of accessible Modbus Registers available in the Optidrive HVAC.
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 4 can be used to control the acceleration and deceleration rate of the drive providing that Fieldbus Ramp Control is
enabled (P5-07 = *
Registers 6 to 24 can be read regardless of the setting of P1-12
Register
Number
Upper Byte
Lower Byte
Read
Write
Notes
1
Command Control Word
R/W
Command control word used to control the Optidrive when operating with Modbus
RTU. The Control Word bit functions are as follows :-
Bit 0 : Run/Stop command. Set to 1 to enable the drive. Set to 0 to stop the drive.
Bit 1 : Fast stop request. Set to 1 to enable drive to stop with 2
nd
deceleration ramp.
Bit 2 : Reset request. Set to 1 in order to reset any active faults or trips on the drive.
This bit must be reset to zero once the fault has been cleared.
Bit 3 : Coast stop request. Set to 1 to issue a coast stop command.
2
Command Speed Reference
R/W
Set-point must be sent to the drive in Hz to one decimal place, e.g. 500 = 50.0Hz
3
Reserved
R/W
No Function
4
Command Ramp times
R/W
This register specifies the drive acceleration and deceleration ramp times used when
Fieldbus Ramp Control is selected (P5-08 = * irrespective of the setting of P1-12. The
input data range is from 0 to 60000 (0.00s to 600.00s)
6
Error code
Drive status
R
This register contains 2 bytes.
The Lower Byte contains an 8 bit drive status word as follows :-
Bit 0 : 0 = Drive Disabled (Stopped), 1 = Drive Enabled (Running)
Bit 1 : 0 = Drive Healthy, 1 = Drive Tripped
Bit 2 : 0 = In Auto Mode, 1 = In Hand Mode
Bit 3 : 0 = Drive Ready, 1 = Drive Inhibit
Bit 4 : Maintenance Time Not Reached, 1 = Maintenance Time Reached
Bit 5 : 0 = Not In Standby (Sleep), 1 = Standby (Sleep) mode active
The Upper Byte will contain the relevant fault number in the event of a drive trip.
Refer to section 15.1 for a list of fault codes and diagnostic information
7
Output Frequency
R
Output frequency of the drive to one decimal place, e.g.123 = 12.3 Hz
8
Output Current
R
Output current of the drive to one decimal place, e.g.105 = 10.5 Amps
9
Output Torque
R
Motor output torque level to one decimal place, e.g. 474 = 47.4 %
10
Output Power
R
Output power of the drive to two decimal places, e.g.1100 = 11.00 kW
11
Digital Input Status
R
Represents the status of the drive inputs where Bit 0 = Digital Input 1 etc.
20
Analog 1 Level
R
Analog Input 1 Applied Signal level in % to one decimal place, e.g. 1000 = 100.0%
21
Analog 2 Level
R
Analog Input 2 Applied Signal level in % to one decimal place, e.g. 1000 = 100.0%
22
Pre Ramp Speed Reference
R
Internal drive frequency set-point
23
DC bus voltages
R
Measured DC Bus Voltage in Volts
24
Drive temperature
R
Measured Heatsink Temperature in °C
10.2.3.
Modbus Parameter Access
All User Adjustable parameters (Groups 1 to 5) are accessible by Modbus, except those that would directly affect the Modbus
communications, e.g.
P5-01 Drive Fieldbus Address
P5-03 Modbus RTU Baud Rate
P5-04 Modbus RTU Data Format
All parameter values can be read from the drive and written to, depending on the operating mode of the drive – some parameters cannot be
changed whilst the drive is enabled for example.
When accessing a drive parameter via Modbus, the Register number for the parameter is the same as the parameter number,
E.g. Parameter P1-01 = Modbus Register 101.
Modbus RTU supports sixteen bit integer values, hence where a decimal point is used in the drive parameter, the register value will be
multiplied by a factor of ten,
E.g. Read Value of P1-01 = 500, therefore this is 50.0Hz.
For further details on communicating with Optidrive using Modbus RTU, please refer to your local Invertek Sales Partner.
10.3.
BACnet MS/TP Communications
Refer to the seperate Optidrive HVAC BACnet User Guide for further information.
