11
Table 14.2. Claim frame format for the WRITE function
(frame length - 8 bytes):
address of
the device
function
0x06
write register address:
write register value
CRC check sum
1 byte
1 byte
2 bytes (HB-LB)
2 bytes (HB-LB)
2 bytes (LB-HB)
Example 14.2.
Entry in a register with address 10 (0xA) with the 0 value: 0x01 - 0x06 - 0x000A - 0x0000 - 0xA9C8
Table 14.3. Response frame format for the READ
function (minimum frame length - 7 bytes):
address of
the device
function
0x04
number of bytes in the
data field (max. 20*2=40
bytes)
data field - register value
CRC check sum
1 byte
1 byte
1 byte
2 bytes (HB-LB)
2 bytes (LB-HB)
Example 14.3
. Response frame for register value equal to 0: 0x01 - 0x04 - 0x02 - 0x0000 - 0xB930
Table 14.4. Response frame format for the WRITE
function (frame length - 8 bytes):
copy of the claim frame for the WRITE function (Table 14.2)
Table 14.5. Special answer
(errors:
function field = 0x84 or 0x83 in the case of the READ function and 0x86 in the
case of the WRITE function, High Byte in the data field = 0):
Error code
(HB-LB in the data field)
Error description
0x0001
non-existing register address
0x0002
erroneous value of parameter to be saved
0x0003
improper function number
Example 14.5.
Error frame for a non-existing read register address:
0x01 - 0x84 - 0x02 - 0x0001 –0x5130
Table 14.6. Map of registers for the MODBUS-RTU protocol
Register address
HEX (DEC)
Value
(HEX or DEC)
Description of register and access type
(R- read only register, R/W - read and write register)
0x00 (0)
-19999 ÷19999 measured value
R
0x01 (1) and 0xC8 (200)
5940
device type identifier (AR594)
R
0x02 ÷ 0x05 (2 ÷5)
-
reserved (do not use)
R
0x06 ÷ 0x13 (6 ÷ 19)
Reading/writing of parameter (
inp
,
filt
,
dot
,…)
Register address = parameter number from Table 9
(chapter 9)
+ 6
R/W
15. CONNECTING THE CONTROLLER TO A COMPUTER AND AVAILABLE SOFTWARE
It may be useful (or necessary) to connect the transducer to a computer in order to configure parameters, which
also enables copying the setting to other transducers of the same type.
As a standard, the transducers are equipped with a
PR
port, which enables connecting to a computer using an
AR956 programmer. Attention should be paid to the configuration of transmission parameters in the options of
the ARSOFT-CFG software.
During the first startup, the (default) transmission parameters should have the following values:
Speed = 2,400 bit/s, MODBUS address = 1.
The following applications are available (on a CD supplied with the AR956 programmer or to be downloaded from
the Internet at
www.apar.pl
,
Download
section, for operating systems Windows Vista/7/8/10):
