Design
The SSW7-HMI permits connection of operator terminals or visualization software
from a serial interface (RS232 level, 4.8 ... 115 Kbaud) with an HMI protocol to an
MPI bus (RS485 level, 187.5Kbaud).
The SSW7-HMI has a 1.2m long connecting
cable, which can be directly plugged into the
CPU connector of the PLC or at any other
point in the MPI network.
A nine-way D-sub connector with a pin
assignment suitable for a standard PC null
modem cable is contained in the housing of
the SSW7-HMI (cable is part of the scope of
supply of the SSW7-HMI).
The SSW7-HMI receives its power supply from
the CPU via the MPI cable. If 24V are not
available at the point of connection or if
several SSW7s are connected to a CPU at the
same time, the 24V power supply can be fed
from an external source.
The 24V connection intended for this purpose (green connector).
The connection to the MPI bus can be extended with an additional cable. For that
purpose, Systeme Helmholz GmbH offers the following products:
SSW7 extension cable, 5m 700-751-6VK11
SSW7 extension cable, 10m 700-751-6VK21
SSW7 extension cable, special length 700-751-6SO11
When extending the MPI bus, please follow the relevant configuring guidelines as
defined in the documentation of your PLC.
The SSW7-HMI and the extension cable do not contain any terminating
resistors.
