Philips System 21 - How to See if Units Are Ready with the Programmed Tasks; How to See if Units Have Data Available

9. HOW TO SEE IF UNITS ARE READY WITH THE PROGRAMMED TASKS
Default, the slaves pull the ready-line low as long as the programmed actions are
not finished. However each slave can be disabled to
pull the ready-line low.
Command
Description
"AID213;R~E" ready-line control enable (default): unit 213 will pull
the ready-line low when not ready.
"AID213;R~D"
ready-line control disable: unit 213 will never pull
the ready-line low (keeps ready passive true).
The state of the ready-line can be read by the master command
"AID; ROY ?".
Addressing System 21 as talker will give as response:
"AID;RDY 0"
"AID;RDY 1"
ready-line is low: the unit(s) are not ready.
ready-line is high: the unit(s) are ready.
If more than one slave controls the rea.4-~ trnor user can appry a status request to
the different
slaves..wtttr'1tf!Jnnn;S ?" to see which ones are ready and which ones
are not
ready·fsee System 21 manual).
10. HOW TO SEE IF UNITS HAVE DATA AVAILABLE
The most appropriate way to check for data availability at a unit is by the following
command:
Command
Description
"AIDnnn;S ?" ask for the status of unit with address "nnn".
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The response is "AIDnnn;S "+ < 9 digits >, where digit number 5 represents data
availability (see
System 21 manual).