Writing n words Instruction, Reply, Address, Words

Writing n words

Instruction

Slave

Function

Address

Number of

Word

Check-

address

0x10

of first

words

bytes

value(s)

sum

word

(max. 2)

CRC16

1 byte

2 bytes

1 byte

x byte(s)

2 bytes

Reply

Slave address

Function 0x10

Address of

Number of

Checksum

first word

words

CRC16

1 byte

2 bytes

Example

Write switch-on threshold (Hys1 = -10)

Word address = 0x0018

Instruction:

CRC16

Reply:

CRC16

Data type “char“	The high byte must be transmitted first.
	Example: Configuration code C111: “9030“
	MOD bus:	0B10 0024 00 02 04 0903
Data type “float“	The following explanations apply under the condition that the master works with the
	IEEE-754 format. Before transmitting a value, the bytes must be exchanged in a way
	that the order corresponds to the presentation for the MOD bus (see illustration below).

M-23 bit normalized mantissa

E-exponent (complement to base 2)

S-Sign-bit; 1 = negative, 0 = positive

MOD-BusMMMMMMMM MMMMMMMM SEEEEEEE EMMMMMMM

Read

Master

SEEEEEEE EMMMMMMM MMMMMMMM MMMMMMMM

(IEEE 754)

7865z13e/1102

Write

Example:
Transmission of decimal value “550“:
MOD bus:	0x80, 0x00, 0x44, 0x09

Following is a description of all process values (variables) with their addresses, data type and type of access.

Where:
R / O	Read only access
R / W	Read and write access
float	Float value (4 bytes / 2 words)
word	Integer (2 bytes / 1 word)

The process values are subdivided into logic areas.

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Siemens Building Technologies	CC1A7865.1en
HVAC Products	31.10.2002