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Endurance
®
Series
Users Manual, Rev. 2.0, Jun 2020
120
14 ASCII Programming
This section explains the
sensor’s communication protocol. A protocol is the set of commands that define all
possible communications with the sensor. The commands are described along with their associated ASCII
command characters and related message format information. Use them when writing custom programs for your
applications or when communicating with your sensor with a terminal program over the digital interface.
14.1 Remote versus Manual Settings
Since the sensor includes a local user interface
– the control panel – the possibility exists for a person to make
manual changes to parameter settings. To resolve conflicts between inputs to the sensor, the following rules are
valid:
•
Command precedence: the most recent parameter change is valid, whether originating from manual or
remote.
•
If a manual parameter
change is made, the sensor will transmit a “notification” string to the host.
(Notification strings are suppressed in multidrop mode.)
•
A manual lockout command is available in the protocols set so the host can render the user interface
“display only” if desired.
All parameters set via the control p
anel, the RS485 or the Ethernet interface are retained in the sensor’s nonvolatile
memory.
Note
When a unit is placed in multidrop mode its manual user interface is automatically locked! It can be unlocked
with the command XXXJ=U <CR>, where XXX is the multidrop address.
14.2 Command Structure
Note
All commands must be entered in upper case (capital) letters!
14.2.1 Timing
After transmitting one command, it is obligatory to wait for the response from the sensor before sending another.
Make sure that a command sent was completely transmitted from the sender before the next command can be
sent. The response time from the Endurance sensor back to the sender depends on the following factors:
•
Operation mode Single or Multidrop, meaning without or with leading Multidrop address bytes in the
response string
•
Communication interface with different transmission speeds:
o
RS485: 1200 bps
– 115.200 bps (~ 120 char/s – 11.520 char/s)
o
Ethernet: max. 100 Mbit/s (~ 10.000.000 char/s)
14.2.2 Requesting a Parameter (Poll Mode)
?E<CR>
“?” is the command for “request”
“E” is the parameter requested
<CR> carriage return (0D
hex
) is closing the request
14.2.3 Setting a Parameter (Poll Mode)
E=0.975<CR>
“E” is the parameter to be set
“=” is the command for “set a parameter”
“0.975” is the value for the parameter
<CR> carriage return (0D
hex
) is closing the setting