Yaskawa Z1000 AC Drive HVAC - Manual (Page 333)

C.8 Accessing Drive Parameters and the Enter Command
u Reading Drive Parameters
Reading drive 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 Drive Parameters
Writing drive 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 reset the KWH Monitor, write a value of “1” to parameter o1-12.
Parameter o1-12 is located at Modbus register 0512H, which is decimal 1298.
Set AV29 to “1298”
Set AV30 to “1”
Set BV55 to “ON”.
u Enter Command
Enter Commands are only required when using AV29 and AV30 to access drive parameters. An Enter command is not required
when reading or writing to the other BACnet objects.
When writing parameters to the drive 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 drive supports two types of Enter commands as shown in Table C.11 .
Table C.11 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 is shut off.
BV56 (Write “ON”) 0900H (Write 0)
Simultaneously writes data into the EEPROM (non-volatile memory) of the drive 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.8 Accessing Drive Parameters and the Enter Command
YASKAWA ELECTRIC TOEP YAIZ1U 03A YASKAWA AC Drive – Z1000 User Manual 333
C
BACnet Communications