Advertisement
When input is set as INHIBIT, module generates INHIBIT signal for SMD when active. If both inputs are
configured as INHIBIT, they can be processed by a logical function chosen in the next drop down box.
Available logical functions are OR, AND and XOR.
When an input is set as KEYIN, module generates three signals - KEYIN OK, KEYIN TIMEOUT and
KEYIN DROPPED - during the each T-R sequence. KEYIN should be always paired with an output
configured as KEYOUT; their primary function is to interface to the keying signals of the Power Amplifier.
When input is configured as the KEYIN, KeyIn timeout field specifies maximum time allowed for KEYIN
to arrive after KEYOUT was generated. If KEYIN does not arrive in time (broken cable, PA error), the
module will generate KEYIN TIMEOUT, SMD will display a small KEYIn message, and prevent
transmission. If KEYIN arrives within timeout, KEYIN OK signal is generated and transmission will be
enabled.
NOTE: If a configuration contains multiple Power Amplifiers driven by one radio/SMD, the SMD will
prevent transmission until KEYIN OK signals have been received from all of the active amplifiers
in the selected (active) TX antenna path.
If KEYIN signal arrives within KeyIn timeout but then drops (which may happen due to error but most
often occurs when an automatic amplifier re-tunes), transmission is inhibited till KEYIN returns to the
active state. During this period the SMD display will show "KEYIN dropped" and the module address.
NOTE: If neither input is used as a KEYIN or INHIBIT, for example if the Power Amplifier doesn't provide
KEYIN signal, KeyIn timeout changes its name and function to Inhibit lead and value sets fixed
time during which module generates a fixed length INHIBIT signal. Inhibit lead time generally
provides protection against hot switching the power amplifier.
IMPORTANT: If the TX path contains more than one Power Amplifier and one or more of them don't
connect KEYIN signal, all Power Amplifiers will have fixed Inhibit Lead time equal to the longest
defined lead time. This time changes dynamically according to selected TX path and presence of
Power Amplifiers in TX path.
O1, O2, OPT
•
These outputs can be configured to function as KEYOUT or PA ON. KEYOUT is the Power Amplifier
PTT (e.g., PAPTT) and PA ON allows ON and OFF control if the the amplifier supports it. The OPT
output only supports the PA ON function. The same parameters are available for both functions:
Tail
Specifies tail time, additional delay at the end of each T-R or Power OFF cycle.
Deactivate if Specifies how the outputs will be handled under two situations.
No user specifies if output will be deactivated if no user (SMD) uses the control box.
Out of bands specifies if output will be deactivated (inhibited) if the TX frequency is out of
the defined frequency range. Normal use of this control is to automatically enable/disable
(turn amplifier on/off or disable generation of KEYOUT signal) according to the frequency
and whether the amplifier is selected.
microHAM © 2016 All rights reserved
50
Advertisement
