Ricoh G157 Service Manual page 222

MAINTENANCE MODE
Selector 2: Recovery from Inactive PC Interface (Not used.)
If the machine recognizes via the STB signal line that the connected PC is powered
off, it will turn the PC interface outputs Low to protect the PC from hazards that
could be caused by weak electric current accidentally flown from the machine.
This selector determines whether or not the machine should recover from the
inactive PC interface to normal interfacing state upon receipt of data from the PC.
Selector 3: PC Power-off Recognition Time (Not used.)
This selector sets the time length from when the machine detects the PC powered
off until it recognizes the detected state as power-off.
If selector 2 is set to "0", it is recommended that selector 3 be set to "1"; otherwise,
the machine may mistakenly detect PC powered off.
Selector 5: Escape from phase C
This selector determines whether or not the machine will escape from phase C
when it detects an RTC (Return to Control) in non-ECM mode or an RCP (Return
to Control Partial page) in ECM mode.
Selectors 6 through 8: Extension of incoming calling signal (CI) frequency band
specified by selectors 1 through 4 on WSW14
At the start of reception, if the machine detects the frequency of a CI signal
specified by selectors 1 through 4 on WSW14, it starts the ringer sounding.
However, the machine may fail to detect the CI signal normally due to noise
superimposed at the time of reception. To prevent it, use selectors 6 through 8 on
WSW36.
If the machine detects higher frequencies than the setting made here, it regards
them as noise and interprets the detecting state as being normal, allowing the
ringer to keep sounding according to the preset number of ringers (until it starts
automatic reception of FAX data in the FAX mode or enters the TAD mode in the
TEL mode).
G157 5-78 SM