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The
MTL646/7 text displays are located in the
hazardous area where they display alphanumeric data &
graphics from a safe area host controller. This is transmitted
by a serial data link passing through an MTL5051 isolating
interface. This serves the dual purpose of isolating the IS
indicator and converting RS232 or RS422 serial data to the
MTL signal level and vice versa. Bi-directional communication
permits operators to acknowledge messages and to request process
action when necessary. If required, an audible or visual alarm
can be connected to attract the operators attention.
A clear dot
matrix display (128 x 64) can display text
(in a number of sizes) and process graphics. The backlight
permits operation during darkness. Operator control can be
provided viea the front panel push buttons or via externa
terminals to remote switches. These can be used for alarm
acknowledgement, or to advance or stop the process.
The controller
maintains master control, requiring all remote display units
to respond to its commands. In multi-indicator applications,
it transmits a block of information which includes the indicator
type, address and data. Data is transmitted in the form of
ASCII characters interpreted by the appropriate ndicator which
either updates the display or responds with a reply such as
indicator status or switch status. In single indicator applications,
the protocol may be simplified to direct data transmission
for communication with less sophisticated host units including
PLCs, dedicated control instrumentation and weighing systems.
The MTL646/7 may be configured to emulate the MTL643/4. Mechanical
compatibility allows direct replacement with panel mounted
MTL644 displays.
Two alarm
outputs are provided for connection to suitable
visual or audible alarm units to attract the operator’s
attention.
The MTL647
field mounting unit is housed in a tough impact-resistant
case designed to withstand the rigours of hostile weather
conditions and harsh industrial environments. Ingress protection
rating is IP66. It can be mounted directly onto a flat surface
or, with an optional kit, onto vertical or horizontal pipes
or posts.
The MTL646
panel mounting unit is designed for DIN standard
72 x 144mm cut-out. The panel/unit seal is rated at IP40 while,
with standard ‘snap-on’ mounting clips, the panel/unit
seal is rated IP40. This can be uprated to IP65 with the optional
IPK68 sealing kit.
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