Communications configuring
3-144
System- and communication configuring D7-SYS - SIMADYN D
Edition 12.2003
"slower broadcast transmitter" is not blocked by a "faster" broadcast
transmitter.
The USS master coupling monitors the delay time of the received
telegram. The time interval between the last character of the transmitted
telegram and the first character of the received telegram is considered to
be the delay time. The maximum permissible delay time is 20 ms. If the
addressed slave does not respond within the maximum permissible delay
time, the USS master coupling flags the receive channel, assigned to this
slave, as being faulted. If a receive channel is not configured, no error
entry is made.
The USS master coupling then transmits a telegram destined for the next
slave.
The error entry for the faulted slave is only reset after the slave receives
the next error-free telegram.
3.13.6
USS master on the T400 technology module
This section describes the special issues which you have to observe
when using the USS master coupling on the T400 technology module.
In this section,
you will only find the differences
over to
Section 13.1
to 13.5
.
The USS master coupling allows you to connect, approx.
−
17 drive converters
or
−
19 OP2 operator control devices,
or
−
8 drive converters
and
8 OP2
As prerequisite for the coupling, you will require a
T400 technology
module (terminals 70..71, serial interface X01
or
terminals 74..75, serial
interface X02)
.
Data transfer uses a half-duplex technique according to the RS485
Standard via a 2-conductor cable.
•
It is
not possible to
simultaneously use
two USS couplings
(USS master, USS slave) on the serial X01 and X02 interface
.
•
You must
set switch S1/8 to the on position
so that you can use the
serial X01 interface
for the USS master coupling.
3.13.6.1
Basis network for the T400 technology module
You must set the switch according to the table below dependent on
whether you are using the T400 technology module as
end node
or
not
as end node
on the USS bus, i.e.
at the end
or
not at the end
of the bus
cable.
Monitoring
mechanisms and
error response
Please
note:
