
3
2.4 Initial Turn-on Response
Digital Output
Once the wiring connections and terminal program settings are complete, the HPB will automatically send the
following response (or similar to) when power is applied. This reply will be generated any time power is applied to
the HPB.
Typical Reply:
?01HPB_ _ 1200HPAa
ring network configuration
?00HPB_ _1200HPAa
multi-drop network configuration
The
?01
or
?00
indicates a default address device called a null address. This HPB has not yet been assigned
an ID number so it assumes the null address.
2.5 Command Format
Any command interaction with the HPB requires electrical connection to the TTL serial communications pins.
There are two basic types of commands action directing commands and information requesting commands.
Theses are described in Commands Section 5
Typical HPB commands have the form *
ddcc = nnn
<cr>
Where: *
is the command header character
dd
is the decimal address of the HPB
cc
is a command (refer to Commands Section 5 for a complete description of commands)
=
equal sign (required in some commands)
nnn
additional characters (required in some commands)
<cr>
carriage return is required to end all commands
(do not type, press the ENTER/RETURN key)
2.6 Step-by-Step Examples
(Only for single HPB connection)
READ SINGLE PRESSURE
Once the HPB is powered up and connected to a computer, enter the following command:
Type:
*
00P1
<cr>
Response:
?01CP=15.458
(ring)
?00CP=15.458
(multi-drop)
Where: *
indicates the start of a command
00
is the null address of the HPB (see note below)
P1
is the command to read the most current pressure
Note:
The ? indicates a response from a null address HPB one which has not been assigned a device ID. A
null address, 00, is coded into each HPB at the factory. When a ring networked null address HPB
responds, it adds one to its address, hence, the response 01. Refer to the
ID
command in Section 5.10
for a description of addresses and responses.
In the reply, the 01 identifies the individual unit address (range 01-89). The CP=15.458 indicates
a compensated pressure of 15.458 psi. Your unit may not show this specific reading, depending on the
applied pressure it is measuring.