Danfoss Metasys N2 Design Guide

A number of data bytes (variable, depending on the type
of telegram) follows.
A data control byte (BCC) completes the telegram.
STX LGE ADR DATA BCC
195NA099.10
Illustration 14.6 Telegram Structure
14.5.3 Telegram Length (LGE)
The telegram length is the number of data bytes plus the
address byte ADR and the data control byte BCC.
•
The length of telegrams with 4 data bytes is
LGE=4+1+1=6 bytes.
•
The length of telegrams with 12 data bytes is
LGE=12+1+1=14 bytes.
•
The length of telegrams containing texts is 10
1)
+n
bytes.
1) The 10 represents the
xed characters, while the n is
variable (depending on the length of the text).
14.5.4 Drive Address (ADR)
Two dierent address formats are used.
The address range of the drive is either 1–31 or 1–126.
•
Address format 1–31
- Bit 7=0 (address format 1–31 active).
- Bit 6 is not used.
- Bit 5=1: Broadcast, address bits (0–4) are
not used.
- Bit 5=0: No broadcast.
- Bit 0–4=drive address 1–31.
•
Address format 1–126
- Bit 7=1 (address format 1–126 active).
- Bit 0–6=drive address 1–126.
- Bit 0–6=0 broadcast.
The slave returns the address byte unchanged to the
master in the response telegram.
14.5.5 Data Control Byte (BCC)
The checksum is calculated as an XOR-function. Before the
rst byte in the telegram is received, the calculated
checksum is 0.
Appendix
VLT
®
HVAC Drive FC 102
228 Danfoss A/S © 11/2017 All rights reserved. MG16C302
1414

Danfoss Metasys N2 Specifications

General

Brand	Danfoss
Model	Metasys N2
Category	DC Drives
Language	English