Videotec SM82A - Manual (Page 51)

Page 13 MNVCSM42A_0408
Point to point connection
This type of connection allows the AUX line to be used to control one or more receivers arranged in cascade
(point-to-point type connection). The AUX line of the matrix should have the termination resistance inserted (see
section 3.4.3). Each receiver in turn should have a RS485 line termination resistance inserted. Each receiver
should have a different address. Configure the receivers with RS485 type communication with the same baud
rate and protocol (Videotec or MACRO) as the Matrix AUX line.
Internally, the receivers can regenerate the received signal and send it on along a new communication line to
the next receiver. Each of the three line sections (L1, L2, L3) is considered independent, and connects only two
devices point-to-point, both with the load inserted, for a maximum distance of 1200 metres. The Matrix - R3
receiver distance can therefore be up to 3600 m (1200 m between the Matrix Aux line and receiver R1, 1200 m
between receiver R1 and receiver R2, and a further 1200 m between receiver R2 and receiver R3, for a total of
3600 m).
N.B. For the connection in question (point-to-point), faulty operation of one of the devices will cause faults in the
receivers that follow.
Multipoint connection
This type of connection allows the AUX line to be used to control one or more receivers connected on the same
line (multi-point connection).
All the receivers connected to the same line should use the same communication protocol RS485.
For each line the following should be taken into consideration:
• the Aux Matrix line should have the load inserted
• only one of the receivers (the one at the end of the line) has the load inserted.
• the total length of the line should not exceed 1200 m.
• each receiver should have a different address
Receivers R1, R2 should not have the termination resistance inserted. The maximum length of the line, from
end to end (from the matrix AUX line to receiver R3), is 1200 metres.
N.B. For the connection in question (multipoint), a fault in one of the devices does not affect the other receivers.
SM82A
SM82A