IQH3A IQ 3U Modular Enclosure
www.snellgroup.com
Installation
Issue 2 Rev 2
Page 30
©
2014 Snell Limited
3.15 Control Panels
A mainframe and the modules that it contains may be controlled by the following methods:
•
Control panels connected via the RollCall communications network.
•
Computers connected via the RollCall communications network.
•
SNMP managers connected via IP.
•
Any combination of the above.
3.15.1 RollCall Communications System
RollCall remote control gives a uniquely powerful and flexible system that can be as simple as
a single rack unit with control panel, or a powerful multi-master, multi-slave configuration with
PC control and monitoring for full station automation.
The RollCall command protocol obtains control information from the IQ module being
addressed. This unique feature ensures that module updates or additions will not require
control system software upgrades - simply plug in and switch on.
When the unit (or module) is powered-up the module will normally assume the same set-up
conditions that existed at the last power-down. This information is provided by non-volatile
memory on the module. Some modules incorporate methods that allow other set-up
conditions to exist on power-up; please consult the information specific to each module for
details.
3.15.1.1
RollCall Network System Details
The IQ Modular system has a flexible and powerful remote control system. The units in the
system are joined via a high-speed network. Each box enclosure is a node on the network. A
single local area network can have a maximum of 255 nodes with any combination of control
panels and modular rack boxes. With the 3U box holding up to 16 cards, the system can
accommodate 4080 (255 x 16) cards. Each box is physically addressed via switches on the
Remote Control Interface.
Network bridges can be used to connect each network to up to 15 others nested up to 4 levels
allowing tens of thousands of networks and millions of units to be joined together.
The IQH3A IQ 3U Modular Enclosure has various interface connections to the RollCall
network:
•
RollNet 75 Ohm coaxial BNC running at 2.5 Mbps. The IQH3A IQ 3U Modular
Enclosure represents a 2 unit load.
•
RollNet RS-485 9-way, D-type connector running at 2.5 Mbps.
•
RollNet RS-485 10 way DIN connector running at 2.5 Mbps.
•
RS-422 or RS-232 port running at up to 115.2 kbps asynchronous.
•
RJ45 Ethernet running at 10/100 Mbps.
The RS-422, RS-232 and RS-485 interfaces share the same D connector. Selection of the
interface mode is made by two banks of DIP switches (SW1 and SW7) located at the rear of
the Gateway card. SW1 is a bank of eight switches (SW1 1-8) and SW7 is a bank of four
switches (SW7 1-4). The Gateway must be removed from the frame to alter the switch
settings.
To select RS-232 mode, SW1 1-7 should be open (toggle up) and SW7 1-4 should be closed
(toggle down). SW1 8 is irrelevant.
To select RS-422 mode, SW1 1-8 should be closed and SW7 1-4 should be open.
To select RS-485 mode, SW1 1-7 should be closed, and SW1 8 and SW7 1-4 should be open.