PSM-500/500L/500LT SCPC Satellite Modem
Maintenance
PSM-500/500L/500LT - Rev. 0.91
Page 4-19
Manual will always turn the carrier off after a change. This option is set in
<Mod: IF – Mute>
.
More directly the setting described is probably set to “Manual” mute mode.
Why can’t I find or see a certain option parameter that is shown in the tables?
Many parameters are only available when another option has been enabled which requires that
parameter. For example, the
<Demod: IF – Sweep Time>
parameter is only visible if the
<Demod: IF – Sweep Mode>
is set to “Search”. These options are shown in the tables as gray
to indicate this status.
Can I control the far end modem from the front panel of a local modem?
The PSM-500 has the ability to control the far end modem (when linked and locked) from a local
modem, but only using the remote control port. This ability requires enabling the Multiplexer
option. Control from the front panel is prone to possible mistakes that would lead to accidentally
setting the remote modem in a state that could not be recovered without going to the remote site.
The far right “Remote” LED is blinking. What does it mean?
The Unit Remote Activity parameters allow setting this lamp to blink when activity is detected on
the USB or serial remote control ports. The same is possible for the “Local” LED using the Unit
Keyboard Activity control.
I seem to have no modulator or demodulator functions available?
There are two reasons that could explain this. First, there are some units sold with only one
function installed for special purposes. These units would have a model number indicating this
such as PST for a Modulator transmit only or PSD indicating a Demodulator receive only.
The other reason could be that the Modulator or Demodulator is disabled. To check and enable if
desired, go to the
<Unit: Config – Modem>
.parameter which shows what is enabled and allows
changing.
What do the abbreviations on the front panel and in the manual mean?
See the abbreviations in FAQ Section E below.
C. Remote Control
Where is the ASCII Control packet structure in the PSM-500?
The PSM-500 and the PSM-4900 modems do not have an ASCII control packet protocol, only the
binary packet protocol. The SnIP however does have a fairly complete command line driven
control method via the “m500ctl” program. In addition the SnIP can potentially control multiple
modems connected via its external RS-485 control port.
Can I use the USB connector at J10 to remotely control the PSM-500?
The USB connector is mainly intended for firmware updates requiring a faster speed than the RS-
232/449 connection can supply. It is possible to control the modem in binary packet mode via the
USB connection. However, this connection does not use or accept addresses in the packet
structure, so it will likely require re-writing your packet routines.
You cannot currently use the USB connection for “Terminal Mode” control.
Is there a “compatibility” mode for the remote control binary packet protocol that looks
like that in the PSM-4900?
Yes. The new PSM-500 design dictated a new structure to implement the significantly greater
number of commands available in the PSM-500. Many items such as the interface structure, data
rates and available options are so different that creating a compatible command set was