Masibus 40005E, User Manual

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User Manual 69
40005E (Enhanced Bargraph Indicator)
REF NO: m42B/om/101
Issue No:02
Modbus Address for Periodic Data fetching:
Sr.
No
Parameter Description
Modbus
Address
Parameter
Type
Access Remarks
1 Data Fetched Periodic Log
42301-
42375
Integer R -
2 Hold Data 42377 Integer R/W -
3 Fetch Data 42376 Integer R/W -
4 Total Periodic Records
42378-
42379
Integer R
42378 [Higher byte]
42379[Lower Byte]
5
Log Roll Over counter for Overlap
Mode
42380 Integer R -
6 Fetch mode 42381 Integer R/W
Description :
o
For Data logging Flash memory is used so data will be fetched in the form of multiple records.
Flash page size is of 256 bytes.
o
The record length is based on Channel number for log selection
o
So in from below equation we can get how many records we can get from 1 page i.e.
Records per page = (Integer) (256 / Total Bytes in 1 record)
o
Example for Fetching data :
Example 1 :
If we have selected 8 channels for periodic data logging so that
Total Bytes in 1 record = 12 + (2 * 8) = 28
Record Per page = 256 / 28 = 9(Odd Number)
So in this case for fetching data, follow below procedure:
1.
Write Hold Data = 1
2. Write Fetch Data = 1
3. Data for first 4 records are loaded into data registers
4. Write Fetch Data = 1
5. Data for record number 5 to 9 will be loaded into data registers
6. Write Fetch data = 1
7. Data for record number 10 to 13 will be loaded into data registers
8. Write Fetch data = 1
9. Data for record number 14 to 18 will be loaded into data registers
10. So in same manner data registers will be filled with 4 records first and then 5 records.
11. After all data fetch Write Hold Data = 0.
Example 2 :
If we have selected 24 channels for periodic data logging so that
Total Bytes in 1 record = 12 + (2 * 24) = 60
Record Per page = 256 / 60 = 4(Even Number)
So in this case for fetching data follow below procedure:
1.
Write Hold Data = 1
2. Write Fetch Data = 1
3. Data for first 2 records are loaded into data registers
4. Write Fetch Data = 1
5. Data for record number 3 - 4 will be loaded into data registers
6. Write Fetch data = 1