WindO/I-NV4 User’s Manual
3-75
5 User Communication
3
Co
m
m
un
ica
tio
n
■
Conversion Type
After calculating the data using the specified calculation type, select the type of conversion for the data from the
following.
■
Number of bytes
After converting according to the specified conversion type, select
1
or
2
for the number of bytes for comparison
data.
Example: BCC for receive command data
This example describes the case of comparing the BCC calculation result for the following receive data with the BCC
part of the receive data.
• Calculation Start Position and Calculation End Position
When Calculation Start Position is 2 and Calculation End Position is 1: Calculates the range
1234
.
• Calculation Type
• Conversion Type
When the BCC calculation result is
0004h
, the converted data is as follows.
Modbus RTU (CRC):
CRC-16 (Generating polynomial:x
16
+x
15
+x
2
+1) is calculated according to the following
procedure. Conversion Type: No conversion, Number of bytes: 2
1. Obtain an exclusive OR (XOR) of 1 byte data at Calculation Start Position and FFFFh.
2. If the least significant bit of the result of step 1 is 0, shift to the right by one bit. If the
bit is 1, shift to the right by 1 bit and obtain XOR of the result and the value (A001h).
3. Repeat step 2 to shift 8 times.
4. Obtain XOR of the next one byte of data and the result of step 3.
5. Repeat steps 2 through 4 until the data at Calculation End Position is processed.
6. Compare the result of step 5 in the order of the lower byte and upper byte.
Example: 1234h
→
34h, 12h
Hexadecimal to ASCII:
Considers the data as binary-coded hexadecimal number and converts it to ASCII data.
No conversion:
No conversion is performed.
XOR:
31h^32h^33h^34h^=04h
ADD:
31h+32h+33h+34h=CAh
ADD (2's Complement): Inverts the bit of CAh+1=36h
Modbus ASCII (LCR):
BA
→
42h, 41h
Modbus RTU (CRC):
BA30h
→
BAh, 30h
1
(31h)
4
(34h)
5
(35h)
2
(32h)
STX
(02h)
3
(33h)
BCC
CR
(0Dh)
1
(31h)
4
(34h)
5
(35h)
2
(32h)
STX
(02h)
3
(33h)
BCC
CR
(0Dh)
(1)
(2)
(3)
(4)
(5)
(6)
Calculation Start Position:
(5)
(4)
(3)
(2)
(1)
(0)
Calculation End Position:
Data used for BCC calculation
0004h
Hexadecimal to ASCII
0
(30h)
Data
4
(34h)
0004h
No conversion
00h
Data
04h
Summary of Contents for WindO/I-NV4
Page 1: ...B 1701 16 User s Manual...
Page 108: ...5 WindO I NV4 Common Operations and Settings 2 76 WindO I NV4 User s Manual...
Page 256: ...7 BACnet Communication 3 148 WindO I NV4 User s Manual...
Page 372: ...6 Screen Restrictions 5 32 WindO I NV4 User s Manual...
Page 390: ...5 Part Library Function 6 18 WindO I NV4 User s Manual...
Page 420: ...3 Text 7 30 WindO I NV4 User s Manual...
Page 628: ...2 Multi State Lamp 9 34 WindO I NV4 User s Manual...
Page 924: ...4 Meter 11 76 WindO I NV4 User s Manual...
Page 990: ...7 Timer 12 66 WindO I NV4 User s Manual...
Page 1030: ...4 Using Data and Detected Alarms 13 40 WindO I NV4 User s Manual...
Page 1098: ...4 Using the Data 15 22 WindO I NV4 User s Manual...
Page 1248: ...5 Restrictions 22 18 WindO I NV4 User s Manual...
Page 1370: ...2 Monitoring on the MICRO I 25 28 WindO I NV4 User s Manual...
Page 1388: ...4 Restrictions 26 18 WindO I NV4 User s Manual...
Page 1546: ...5 Module Configuration Dialog Box 30 36 WindO I NV4 User s Manual...
Page 1614: ...3 Settings 34 14 WindO I NV4 User s Manual...
Page 1726: ...5 Text Alignment A 10 WindO I NV4 User s Manual...