Campbell Scientific CR6 CR6 Measurement and Control System - Page 268

TerminationChar, MaxNumChars

Page 268 highlights

Section 7. Installation 268 packet. For this reason SerialOpen() leaves the interface powered up so no incoming bytes are lost. When the CR6 has data to send with the RS-232 port, if the data are not a response to a received packet, such as sending a beacon, it will power up the interface, send the data, and return to the "dormant" state with no 40 second timeout. Q: How can I reference specific characters in a string? A: Accessing the string using the third dimension allows access to the remainder of the string that starts at the third dimension specified. For example if, TempData = "STOP", then, TempData(1,1,2) = "TOP", TempData(1,1,3) = "OP", _ TempData(1,1,1) = "STOP" To handle single-character manipulations, declare the string with a size of 1. That single-character string can be used to search for specific characters. In the following example, the first character of a larger string is determined: Public TempData As String * 1 TempData = LargerString If TempData = "S" Then A single character can be retrieved from any position in a string using the third dimension. To retrieve the fifth character of a larger string, follow this example: Public TempData As String * 1 TempData = LargerString(1,1,5) Q: How can I get SerialIn(), SerialInBlock(), and SerialInRecord() to read extended characters? A: Open the port in binary mode (mode 3) instead of PakBus-enabled mode (mode 0). Q: Tests with an oscilloscope showed the sensor was responding quickly, but the data were getting held up in the internals of the CR6 somewhere for 30 ms or so. Characters at the start of a response from a sensor, which come out in 5 ms, were apparently not accessible by the program for 30 ms or so; in fact, no data were in the serial buffer for 30 ms or so. A: As a result of internal buffering in the CR6 and / or external interfaces, data may not appear in the serial port buffer for a period ranging up to 50 ms (depending on the serial port being used). This should be kept in mind when setting timeouts for the SerialIn() and SerialOut() instructions, or user-defined timeouts in constructs using the SerialInChk() instruction. Q: What are the termination conditions that will stop incoming data from being stored? A: Termination conditions: • TerminationChar argument is received • MaxNumChars argument is met

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Section 7.
Installation
packet.
For this reason
SerialOpen()
leaves the interface powered up so no
incoming bytes are lost.
When the CR6 has data to send with the RS-232 port, if the data are not a
response to a received packet, such as sending a beacon, it will power up the
interface, send the data, and return to the "dormant" state with no 40 second
timeout.
Q
: How can I reference specific characters in a string?
A
: Accessing the string using the third dimension allows access to the remainder
of the string that starts at the third dimension specified.
For example if,
TempData = "STOP",
then,
TempData(1,1,2) = "TOP", TempData(1,1,3) = "OP", _
TempData(1,1,1) = "STOP"
To handle single-character manipulations, declare the string with a size of 1.
That
single-character string can be used to search for specific characters.
In the
following example, the first character of a larger string is determined:
Public
TempData
As String
* 1
TempData = LargerString
If
TempData = "S"
Then
A single character can be retrieved from any position in a string using the third
dimension.
To retrieve the fifth character of a larger string, follow this example:
Public
TempData
As String
* 1
TempData = LargerString(1,1,5)
Q
: How can I get
SerialIn()
,
SerialInBlock()
, and
SerialInRecord()
to read
extended characters?
A
: Open the port in binary mode (mode 3) instead of PakBus-enabled mode
(mode 0).
Q
: Tests with an oscilloscope showed the sensor was responding quickly, but the
data were getting held up in the internals of the CR6 somewhere for 30 ms or so.
Characters at the start of a response from a sensor, which come out in 5 ms, were
apparently not accessible by the program for 30 ms or so;
in fact, no data were in
the serial buffer for 30 ms or so.
A
: As a result of internal buffering in the CR6 and / or external interfaces, data
may not appear in the serial port buffer for a period ranging up to 50 ms
(depending on the serial port being used).
This should be kept in mind when
setting timeouts for the
SerialIn()
and
SerialOut()
instructions, or user-defined
timeouts in constructs using the
SerialInChk()
instruction.
Q
: What are the termination conditions that will stop incoming data from being
stored?
A
: Termination conditions:
TerminationChar
argument is received
MaxNumChars
argument is met
268