Manual

10 CMVLC401A
Commissioning
5 LECOM Protocol Details
5.1 LECOM - A/B Protocol Description
The LECOM-A/B protocol is used to exchange data between SMV controllers and a host. The LECOM-A/B protocol is
based on DIN 66019, ISO 1745 and ANSI X3.28 (category 2.5 and A2, A4). These standards are similar to each other
and describe the control mode of a transmission section of a transmission system.
The host (the master) can communicate with a slave (SMV controller) in three modes:
• RECEIVE (refer to 6.2)
• SEND (refer to 6.3)
• BROADCAST/MULTICAST (refer to 6.4)
The controllers communicate by means of the ASCII code:
0 1 2 3 4 5 6 7 8 9 0 B C D I F
0 NUL SOH STX ETX EOT ENQ ACK BEL BS TAB LF VT FF CR SO SI
1 DLE DC1 DC2 DC3 DC4 NAK SYN ETB CAN EM SUB ESC FS GS RS US
2 space ! “ # $ % & ‘ ( ) * + , - . /
3 0 1 2 3 4 5 6 7 8 9 : ; < - > ?
4 @ A B C D E F G H I J K L M N O
5 P Q R S T U V W X Y Z [ \ ] ^ _
6 ‘ a b c d e f g h i j k I m n o
7 p q r s t u v w x y z { I } ~ DEL
Example:
“EOT” = 02
hex
= 2
dec
Character “ 1” = 31
hex
= 49
dec
5.2 Controller address (AD1, AD2)
One or more bus devices (slaves) can be selected by means of the controller address, which is 2 bytes (AD1, AD2) long.
The LECOM-A/B protocol supports the broadcast telegrams, i.e. a telegram is sent to a group or all other bus devices.
For this, controller addresses are reserved (refer to BROADCAST, 6.4). Controller addresses have the following structure:
AD1 AD2
The abbreviations have the following meanings:
AD1 ASCII ten-digit of the slave address (0 ... 9; 30 ... 39
hex
)
AD2 ASCII one-digit of the slave address (0 ... 9; 30 ... 39
hex
)