Yaskawa AC Drive P1000 Bypass Technical Manual - Manual (Page 301)

C.7 Accessing Bypass Parameters and the Enter Command
u Reading Bypass Parameters
Reading bypass parameters not listed in the analog or digital objects is accomplished using AV29 and AV30 as shown below:
1.
In decimal, write the desired Modbus register to AV29.
2.
In decimal, read the value at the given register from AV30.
For example, to read the Frequency Reference Upper Limit, read from parameter d2-01.
Parameter d2-01 is located at Modbus register 0289H, which is decimal 649.
Set AV29 to “649”
Read AV30 to get the value.
u Writing Bypass Parameters
Writing bypass parameters not listed in the analog or digital objects is accomplished using AV29, AV30, and BV55 or BV56
as shown below:
1.
In decimal, write the desired Modbus register to AV29.
2.
In decimal, write the value to be written into AV30.
3.
At this point the value is written to the drive, but the location is pending. If necessary, write in more values this way,
then the drive will accept these settings by one of two methods:
Set BV55 to “ON” to move data to active memory.
Set BV56 to “ON” to move data into active memory and save to non-volatile memory.
For example, to enable the loss of load function, write a value of “1” to parameter Z1-31.
Parameter Z1-31is located at Modbus register 85E4H, which is decimal 34276.
Set AV29 to “34276”
Set AV30 to “1”
Set BV56 to “ON”.
u Enter Command
Enter Commands are only required when using AV29 and AV30 to access bypass parameters. An Enter command is not
required when reading or writing to the other BACnet objects.
When writing parameters to the bypass from a controller using BACnet communications, parameter H5-11 determines if an
Enter command must be issued to enable these parameters. This section describes the types and functions of the Enter
commands.
n Enter Command Types
The bypass supports two types of Enter commands as shown in Table C.10 .
Table C.10 Enter Command Types
BACnet Object Modbus Address Description
BV55 (Write “ON”) 0910H (Write 0)
Writes data in the RAM only. Parameter changes are lost when the drive or bypass is
shut off.
BV56 (Write “ON”) 0900H (Write 0)
Simultaneously writes data into the EEPROM (non-volatile memory) of the drive or
bypass and enables the data in RAM. Parameter changes remain after cycling power.
Note: The EEPROM can only be written to 100,000 times, so it is recommended to limit the number of times writing to the EEPROM. The Enter
command registers 0900H and 0910H are write-only and if these registers are read, the register address will be invalid. However, BACnet
objects BV55 and BV56 can be read without error.
C.7 Accessing Bypass Parameters and the Enter Command
YASKAWA SIEP YAIP1B 01A YASKAWA AC Drive – P1000 Bypass Technical Manual 301
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BACnet Communications