420 Series RS232 Encoder Engineering Manual
420 Series Encoder Manual Version v1.9 Oct 2018 Page 2 of 22
Product Overview
The Storm 420 Series Encoder provides a serial interface between keypad and host system. It can be supplied either as
a separate encoder module or pre-assembled into a Storm keypad to suit end user requirements.
Features / Specifications
Input Power + 5V ± 0.25V dc
RS232 Output via 6 pin Molex 2.54mm (.100") Pitch KK® Series Connector
Drives Powertip 80 Character LCD Display from keypad
Direct connection to underpanel mounted 12 key, 16 key, 20 key Storm Keypads.
Ribbon Cable needed for top panel fixing 4 key, 12 key, 16 key Storm Keypads
Overall Footprint 89mm x 66mm
Mounting Centres at 43.2mm and 73.5mm (3mm holes provided for pcb standoffs)
Electromagnetic Compatibility (EMC)
Storm 420 Series Encoders are classified as a component with regard to the European Community EMC regulations. It is
the equipment manufacturers responsibility to ensure that systems using the Storm 420 Series Encoder are compliant
with the appropriate EMC standards.
If the electronic system requires input protection against high voltage transients (to meet CE requirements) it is
recommended that an external interface board is located at the point where the external wiring enters the electronic
system enclosure.
Using the 420 Series Encoder with Storm 5000 Series Integrated Keypads
As a combination the Storm Integrated Keypad/ Display Module with Encoder forms a complete serial communications
device. Alphanumeric output from the unit is communicated via the familiar RS232 physical link layer.
The keypad has 20 keys including ten numeric keys and a further ten special function keys. The LCD module displays 80
characters across 4 lines. Both the keypad and LCD module may be backlit from the controller board.
The module has been designed in such a way that it can be used as part of an embedded application, possibly using a
separate host microcontroller or PC to communicate with the module. Alternatively it may be used as an input interface
since the keypad and LCD functions have been designed to be familiar to most users.
The keypad is arranged as a 5-row, 4 column matrix and is scanned and debounced by the module’s built-in
microprocessor. The debounce filter is set at 64ms. No typematic key rollover function is implemented. Multi-key lockout
is, however, implemented in the firmware.
Use of 420 Series Encoder to provide RS232 output from Storm K Range Keypads
When used with any Storm Interface matrix keypad, the encoder can either be fitted directly to the rear of the keypad, or
connected via a ribbon cable. Please note that the cables required to connect a keypad to the encoder are custom cables
and are not provided by Storm.
The encoder can either be fitted directly to the rear of a standard Storm K Range Keypad, or remotely by a ribbon cable.
Where Storm K Range Keypads are underpanel mounted the 420 Encoder can be directly connected, requiring no
additional mounting hardware.
The overall depth required to house the 420 Encoder is 32mm (1.25in) when measured from back of keypad.
Where Storm K Range Keypads are fixed to a panel surface, a ribbon cable and mounting hardware are required (these
items not included with encoder)
