INVT IPE300 Series, Opeartion Manual

Page: 298 / 383

IPE300 series engineering VFD Communication protocol
-287-
The fieldbus scale depends on the number of decimal places in the value specified in "Setting range"
or "Default". If there are n decimal places in the value, the fieldbus scale m is the nth-power of 10.
Take the following table as an example, m is the value of 10 to the power of n. Take the following table
as an example.
Function
code
Name Description Default Modify
P01.20 Wake-up-from-sleep delay 0.0
–3600.0s (valid when
P01.15 is 2) 0.0s
○
P01.21 Power-off restart selection
0: Disable restart
1: Enable restart
0
○
If "Setting range" or "Default value" contains one decimal, the fieldbus scale is 10. If the value
received by the upper computer is 50, "Delay of auto fault reset" of the rectifier is 5.0 (5.0=50/10).
To set "Wake-up-from-sleep delay" to 5.0s through Modbus communication, you need first to multiply
5.0 by 10 according to the scale to obtain an integer 50, that is, 32H in the hexadecimal form, and
then send the following write command:
VFD
address
Write
command
Parameter
address
Parameter
data
CRC
01 06 01 14 00 32 49 E7
After receiving the command, the VFD converts 50 into 5.0 based on the fieldbus scale, and then sets
"Wake-up-from-sleep delay" to 5.0s.
For another example, after the upper computer sends the "Wake-up-from-sleep delay" parameter
read command, the master receives the following response from the VFD:
VFD
address
Read
command
Parameter
data
CRC
2-byte
data
01 03 02 00 32 39 91
The parameter data is 0032H, that is, 50, and therefore 5.0 is obtained based on the fieldbus scale
(50/10=5.0). In this case, the master identifies that "Wake-up-from-sleep delay" is 5.0s.
9.4.7 Error messages
Operation errors may occur in communication-based control. For example, some parameters can
only be read, but a write command is sent. In this case, the VFD returns an error message response.
Error message responses are sent from the VFD to the master. The following table lists the codes and
definitions of the error message responses.
Code Name Meaning
01H
Invalid
command
The command code received by the upper computer is not allowed to
be executed. The possible causes are as follows:
 The function code is applicable only on new devices and is not
implemented on this device.
 The slave is in faulty state when processing this request.