HVG-2020A Instruction Manual
Page 21 of 29
5.2.7.2.
RS485 Mode Responses
In RS485 mode, all responses and error messages from commands sent using the broadcast address
(0x99) will be suppressed. The S5 command is an exception to this rule; when the device is the only
HVG-2020A on the bus, the command *99 S5 can be used to get the device’s address.
Other than the above behavior, responses will be no different than responses in RS232 mode. There
will be no address in responses.
5.2.8. Commands
5.2.8.1.
Reporting Commands
P
Pressure
Returns the current piezo sensor pressure in the units specified in S22.
P1
Start Pressure Streaming
Causes pressure readings to be output every 1/2 second.
P0
Stop Pressure Streaming
Stops the 1/2 second pressure reading output.
5.2.8.2.
System Commands
A
Device Address (Read/Write)
The RS485 address (also given in S5). For backward compatibility. The same as S5.
BAUD=
(Write Only) Set the baud rate
Sets the baud rate and stores it in non-volatile memory. Valid options are: 9600, 19200,
38400, 57600 and 115200
H
High Setpoint (Read/Write)
This is the value above which the high setpoint will become active. The same as S21.
L
Low Setpoint (Read/Write)
This is the value below which the low setpoint will become active. The same as S20.
U
Pressure Units (Read/Write)
Returns the current pressure unit name in text. The same as S22. To set the pressure unit
that the gauge is displaying, a numeric value is used as follows:
1 = TORR
2 = MBAR
3 = KPA
4 = PSIA
5 = PSIG
6 = ATM
7 = BAR
8 = PA