Commands
2014-
02
55
I&M Data
Figure 7.8
7.6
Command execution
The controller initiates an identification command. The control interface executes the new
command if the data has changed since the last read-out. If the control interface is scheduled
to execute a command a number of times, the toggle bit must be inverted. Only then does the
device sense that the command has to be executed again.
If the control interface detects a new command, it sets the status in the input field to FFh. The
reply counter value increases by 1. The status is displayed after the control interface executes
the commands.
The toggle bit of the response is the same as the toggle bit of the command.
When new data becomes available, the previous data is overwritten. The reply counter value
increases by 1. In the event of an overflow, the reply counter is reset to its start value (01h).
New commands may only be sent to an output field after the response from the previous
command is read.
An overview of the telegram structure with command, command confirmation and response is
provided below:
I&M data 1 = system ID
location ID
I&M data 2 = installation date
I&M data 3 = additional information
