INSTRUMENT MANUAL
VACUUM GAUGE MODEL MM200
160Phone:(215) 947-2500 fax:(215) 947-7464 e-mail:sales@televac.com web site:www.televac.com
MM-200_im REV M
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TELEVAC
Most "?<cr>" responses will be preceded by a letter indicating the reason for the rejection of the command. The
following list gives the definitions of those letters:
A Atmospheric correction only allowed for 4A gauges.
C A non number was where a number should have been.
D Disallowed, usually by the configuration of the unit.
L
Value inputted was too large.
N Number not in range.
O Input buffer overloaded.
R Command not recognized.
S Wrong sensor type.
The RS232 communication protocol requires eight bits of data, one start bit and one stop bit. The use of parity is
optional. The parity bit, if used, occupies the eighth bit of data, so that depending on the communications software
used, the data length may have to be changed to seven bits (as the parity bit is then added after the seventh bit).
The default data rate on a new unit is 9600 baud, but may be changed by way of the communications inter-face to
300, 600, 2400, 4800, or 9600 baud. The baud rate can be stored for default on power up. Alternate baud rates
can be factory supplied.
A description of the various commands follows. They are separated into the different categories.
604 RS232/RS485 COMMANDS
"BF<cr>"
1. Exit burst mode. This command causes the processor to exit the burst mode.
See the next two commands for a description of the burst mode.
"BN<cr>"
2. Enter the burst mode. This command causes the processor to go into the burst
mode. The burst mode provides a means to dump the readings of all processors
in a compact and rapid manner while still in ASCII form. There are some restric-
tions on the use of the burst mode. If two relay modules are installed, (eight
relays) then bursh mode is not available. If one relay board is installed (four re-
lays), then up to seven sensors can be accommodated. If no relay modules are
installed, then a full complement of ten sensors can be accommodated. If only one
relay module is installed, it must be designated as relay module #1.
This command can be stored so that at power up, the modular unit will be in the
burst mode. Storing the "BF" command will cancel the storing of this command.
"BO<cr>"
3. Output data in the burst mode. This command causes an uninterrupted dump of
the data of all installed sensors. The data is stored in RAM so there is no need to
wait for any sensors to be measured for a response from this command.