3. SPECIFICATIONS
MELSEC-A
3-7
Point
In configurations that use multiple master stations (multimaster configuration), when reconnecting
a cable after disconnecting a PROFIBUS cable for 1 master that is exchanging data at a low baud
rate, the communications of the master for which the cable is not disconnected could stop and
the slave output could be turned off. To prevent this, the master PROFIBUS cable must be
secured with a screw.
In addition, there is a high possibility that the above phenomena can be avoided if care is taken
with the following points when configuring a system.
(1) Set the slave watchdog timer setting value to larger than (T
T
r
×
G)/BR. However,
T
T
r : Target token rotation time (Unit: Bit Time)
G :
Gap update factor
BR : Baud rate (Unit: bps)
(2) Use a high baud rate.
(3) The HSA (Highest Station Address) value is made to match the maximum station No. that is
actually connected.