Lenze EMF2102IB - Manual (Page 56)

Appendix
8-24
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8.3.4 BROADCAST / MULTICAST
In a bus network, the command BROADCAST is to address all devices or a group of devices
(multicast) at the same time. The structure of the BROADCAST telegram is similar to the structure
of the SEND telegram. The only exception is that it does not return an acknowledgement.
The devices can be selected via their controller addresses. The following controller addresses are
reserved for a BROADCAST telegram:
controller addresses controller address of
groups
ASCII character
(reserved)
groups
AD1 AD2
00 all ”0” ”0”
10 11 to 19 ”1” ”0”
20 21 to 29 ”2” ”0”
30 31 to 39 ”3” ”0”
40 41 to 49 ”4” ”0”
50 51 to 59 ”5” ”0”
60 61 to 69 ”6” ”0”
70 71 to 79 ”7” ”0”
80 81 to 89 ”8” ”0”
90 91 to 99 ”9” ”0”
Example for a BROADCAST telegram
All controllers are to be stopped when setting controller enable (code number C40 = 0).
The host send the following BROADCAST telegram:
EOT 0 0 STX 4 0 0 ETX BCC
The controllers do not return an acknowledgement.
8.3.5 Monitoring of the slave response
The master monitors the selected slave. The slave must return a response within a defined
time.Under the following circumstances the slave does not return a response to the master (time
out):
•
The controller address could not be recognized
•
A fault (e.g. parity fault) had been detected in one or several characters, including the
character ” ENQ”
•
The transmission path is faulty
•
A BROADCAST telegram had been sent
•
The hardware does not work properly
If the master does not receive a response within a defined period of time, the transmission is tried
again. The number of repetitions is limited.
The monitoring time in the master should be approx. twice as long as the maximum response time.
8.3.6 Transmission faults
After a transmission fault, the master can read C0068 and evaluate the communication error in bit
4
¼7.
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