JBUS protocol (continued)

Function 6: writing a word

request

 

slave address

6

 

word address

word

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1 byte

 

1 byte

 

2 bytes

2 bytes

 

 

 

 

 

 

 

 

 

 

 

 

 

response

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CRC 16

2 bytes

slave address

6

word address

word

CRC 16

The response is echoed acknowledging that the word sent has been received.

example

Writing the value 1000 into the word location 810H of slave at address 50H

50

06

08 10

10 00

8A 2E

Function 8: reading error diagnosis counters

Each slave manages a set of nine 16 bit counters for error diagnosis (see opposite):

- request / response:

slave address

8

 

sub-function

data

 

CRC 16

 

code

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1 byte

1 byte

2 bytes

-the slave must echo the request

-reset error diagnosis counter

-read the total number of:

received frames with CRC error (CNT 1)

received frames with CRC error (CNT 2)

number of exception responses (CNT 3)

frames addressed to the station (CNT 4) (not including broadcast)

broadcast requests received (CNT 5)

number of NACK responses (CNT 6) unit not ready responses (CNT 7)

illegal characters (CNT 8)

 

 

2 bytes

2 bytes

 

 

 

 

 

 

 

 

 

 

00

XYZT

X, Y, Z, T are user

 

 

 

 

defined (transmission

 

 

 

 

parameters)

0A

0000

 

0B

XXXX

 

0C

XXXX

 

0D

XXXX

requests:

 

 

 

 

0E

XXXX

XXXX equals 0000

response:

 

 

 

 

0F

XXXX

XXXX is the counter

value

 

 

 

 

10XXXX

11XXXX

12XXXX

6739389EN/FB - Page 11

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Image 11
APC 6000 user manual Function 6 writing a word, Function 8 reading error diagnosis counters