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has been sent; the device will ignore all characters. A Backspace (0x08) erases the previous character,
but some Serial Communication Software will need to be configured to erase from the display.
Spaces are ignored unless they are part of a text field, e.g. "S 5 4 =
field to "t e s t", not "test". Note that the leading spaces before the first t are ignored; the command
is equivalent to S54=t e s t.
Commands can be entered in upper case, lower case, or mixed case, so s54 = S54 and sTaTuS = STATUS.
Some items can be changed by the user: for example, S20 Low Relay Setpoint. To change an item,
enter the item to be changed followed by the equals sign '=' followed by the new value, e.g. S20=60.
Some items which affect calibration cannot be changed by the user; "ACCESS DENIED" will be returned
when trying to change these values.
Text Strings are limited to 63 characters.
5.2.6. RS232 / RS485 Mode
The active mode is determined by the touch screen, the push-button (see Section 2.4) or the
commands ENABLERS485 and DISABLERS485. RS232 mode does not support addressing, so commands are
entered as described in the command description.
In RS485 mode, multiple devices can be on the same bus; an address is required to select the device to
which commands are directed. The HVG-2020A device address is stored in S5. The address is a two-
digit hexadecimal value which can be in the range 0x01 to 0x98 and 0x9A to 0xFF; the factory default is
x01.
The address is required at the beginning of every command and is entered in the format *NN where NN
is the two-digit hex address stored in S5 of the target device. As an example, if you want to read the
Sensor List from the device with address 0x02, send the command *02 SL. The HVG-2020A will accept a
one-digit address, but this could cause problems; *2 SL will work the same as *02 SL, but *2 A will be
interpreted as *2A which is addressing device 2A, not 2. ("A" returns the device address.) In this case,
you must enter *02 A because A is a valid hex digit. Note that *02A works the same as *02 A as
discussed above.
Address 0x99 is used for broadcasting – all devices will process the command. For example, the
command *99 S14=3 will command all attached HVG-2020A gauges to display 3 decimal places.
NOTE: The *99 address will not yield responses to query commands on the RS485 bus (except
S5), because multiple instruments will try to respond simultaneously.
See the Digital Connection section 2.3.5 earlier in this manual for more information
5.2.7. Response Format
Responses may be set to either Cryptic or Verbose; this is controlled by using the S112 command
(S112=1 for Verbose, S112=0 for Cryptic) or with the ENABLEVERBOSE and DISABLEVERBOSE commands.
Cryptic responses include only the requested item's value.
Verbose responses include descriptive text along with the item's value. If units are associated with the
item, the units will also be displayed. The SL and SFL commands are always verbose.
5.2.7.1.
The Response Line Termination character(s) is (are) appended to each line returned from the HVG-
2020A; the default is a Carriage Return, but this can be changed via S65 to one of the following:
For carriage-return (default), enter "S65=x0D".
For line feed, enter "S65=x0A".
For carriage-return linefeed, enter "S65 =x0D0A".
HVG-2020A Instruction Manual
Response Line Termination
t e s t" will set the Comment
Page 20 of 29
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