CAEN
Electronic Instrumentation
UM2619 – N1419 User Manual
25
It is also possible to build a daisy chain of up to 32 N1419’s, with the first module connected to the PC RS232 port
and the subsequent ones daisy chained through the COMM IN/OUT, as explained on p.12; in this case
communication with the chained modules is achieved through the USB - RS485 Communication Protocol . All
modules must be assigned a LOCAL BUS ADDRESS (see p.15) different from one another and the last one must be
terminated (see p.36).
RS485 communication
Fig. 42: RS485 communication diagram
The COMM IN / OUT connectors implement a RS485 type LOCAL BUS which allows to build a 32 modules daisy
chain. This can be achieved through the following steps:
−
Connect the connector OUT of a module to corresponding the IN connector of the next one
−
Assign to each module a different address (LOCAL BUS ADDR); see p. 15
−
Ensure that the LOCAL BUS BIT RATE is the same for all modules; see p. 15
−
Terminate the first and the last module in the chain (see p.36)
The module control can be done in one of the following ways:
o
by connecting a RS485 controller to the first module’s COMM IN port
o
by connecting a RS485 controller to the last module’s COMM OUT port
Communication with the chained modules is achieved only through the USB - RS485 Communication Protocol, see
p.24.
Ethernet communication
Fig. 43: Ethernet communication diagram
It is possible to communicate via Ethernet with one or more daisy chained N1419 modules through the NIM8301
Fan Unit
6
. Communication via Ethernet is possible only through the USB - RS485 Communication Protocol. The
single module or the first module of the daisy chain must be connected to the Fan Unit RS232 port through the
cable adapter (see figure below) connected to the N1419 COMM IN port; SW[200, 201] switch placed on the
Microcontroller board inside the module must be set to Adaptation ON (see p.34).
6
The CAEN Mod. NIM8301 is a 7U (5+2) full size NIM crate (19”-12 slot) available with pluggable 300W and 600W power supplies, ventilated by
pluggable 2U fan unit. Remote control and monitoring take place through CAN bus, Ethernet, USB and RS232 interfaces.