Specifications

Section 13. Telecommunications and Data Retrieval
13-2
13.2 Protocols
The primary telecommunication protocol for the CR1000 is PakBus (Section
14 PakBus Overview). ModBus and DNP3 are also supported on board
(Section 15). CANBUS is also supported when using the Campbell Scientific
C
ANBUS communications module.
13.3 Initiating Telecommunications
Telecommunications sessions are usually initiated by the user or PC. Once
telecommunications is established, the CR1000 issues a series of commands to
send programs, set clocks, and collect data. Because data retrieval is managed
by the PC, several PC’s can have access to a single CR1000 without disrupting
the continuity of data. PakBus allows multiple PCs to communicate with the
CR1000 simultaneously when the proper telecommunications networks are
installed.
When using PC200W, PC400, and RTDAQ software, the user always initiates
telecommunications. With LoggerNet software, the user or LoggerNet, by way
of a scheduler, may initiate telecommunications. Some applications, however,
require the CR1000 to initiate a telecommunications session. This feature of
the CR1000 is known as Callback.
For example, if a fruit grower wants the CR1000 to contact him with a frost
alarm, the CR1000 can instigate telecommunications. Telecommunications is
often initiated by calling the PC, but can also be initiated through email / text
messaging to the grower’s cell phone, audible voice synthesized information
over telephone, or by calling a pager. Callback has been utilized in
applications including Ethernet, land-line telephone, digital cellular, and direct
connection. For more information on available Callback features, contact a
Campbell Scientific applications engineer or search for “Call-back”
information in CRBASIC Editor Help.
When using the ComME communications port with non-
PakBus protocols, incoming characters can be corrupted
by concurrent use of the CS I/O for SDC communication.
PakBus communication uses a low level protocol of a
pause / finish / ready sequence to stop incoming data while
SDC occurs.
Non-PakBus communication includes PPP protocol,
ModBus, DNP3, and generic CRBASIC driven use of CS
I/O.
Usually unnoticed, a short burst of SDC communication
occurs at power up and other times when the datalogger is
reset, such as when compiling a program or changing
settings that require recompiling. This SDC activity is the
datalogger querying the SDC to see if the CR1000KD
Keyboard / Display, an SDC device, is attached.
When DevConfig and PakBus Graph retrieve settings, the
CR1000 queries the SDC to determine what SDC devices
are connected. Results of the query can be seen in the
DevConfig and PakBus Graph settings tables. SDC
queries occur whether or not an SDC device is attached.
CAUTION