Dynacord DSA 8805 - Handbuch (Seite 17)

DIGITAL SYSTEM AMPLIFIER
Owner‘s Manual 17
3 STATUS LED
The STATUS LED is for monitoring the communication on the CAN bus. The LED blinks rhythmically every 3
seconds, when the module’s address is set to “00“, which means that it is disconnected from the CAN bus
and software control. The LED blinks rhythmically in intervals of one second, when an address in the range of
01 to 250 has been assigned to the module and there has not yet been any activity on the CAN bus. As soon
as communication on the CAN bus is recognized, the LED lights for at least 100 ms, when the power
amplifier sends data on the CAN bus.
4 REMOTE CAN BUS Connection
The RCM-810 module provides two RJ-45 sockets for connecting to the REMOTE CAN BUS. These sockets
are connected in parallel and serve as inputs as well as for daisy-chaining the devices on the remote
network. Cabling in a rack system can be established using commercially available RJ-45 network cables.
However, CAN guidelines have to be observed for longer cable lengths. Both ends of the CAN bus must be
terminated using 120
Ω terminating plugs.
The CAN bus allows using different data rates, whereas the data rate is inversely proportional to the bus
length. For smaller network setups, data rates can be as high as 500 kbit/s. For broader networks, reducing
the data rate becomes necessary (down to the minimum data rate of 10 kbit/s).
The following table illustrates the relation between data rate and bus length or network size. The use of CAN repeaters is
strongly recommended for busses that exceed 1000 meters in length.
5 CONTROL PORT
The CONTROL PORT of the RCM-810 provides two control inputs, two control outputs and reference
connections for +5V and ground. The control inputs are configurable via IRIS-Net. They can be used for
example for switching between power on / standby modes. The two control contacts IN 1 and IN 2 are
internally connected via pull-up resistors and carry +5V (open). The control inputs can be activated using
external switches, pushbuttons or relays to connect them to ground potential. The two control outputs OUT 1
and OUT 2 are open collector outputs, which are highly resistive in the non-active state (off). In active state
(on) the outputs are connected to ground. The control outputs are configurable via IRIS-Net and are used to
signal internal states. LEDs, indicators or relays can be driven directly. The +5V reference connector
provides voltage supply for connected components.
NOTE:
The data rate of the CAN bus is preset to 10 kbit/s.
Transfer rate (in kbit/s) Bus length (in m)
500 100
250 250
125 500
62,5 1000
20 2500
10 5000
Table 4.3: Transfer rate and bus length
Illustration 4.2: Pin-assignment of CAN jack and CAN plug
CAUTION:
The maximally allowable current at the +5V output is 200 mA.