Campbell Scientific CR800 and CR850 Measurement and Control Systems - Manual (Page 63)

Section 5. System Overview
63
5.1.3.5 Communications Ports
Read More! See sections RS-232 and TTL Recording
(p. 308),
Telecommunications
and Data Retrieval
(p. 332),
and PakBus Overview
(p. 334).
The CR800 is equipped with four communications ports. Communication ports
allow the CR800 to communicate with other computing devices, such as a PC, or
with other Campbell Scientific dataloggers.
Note RS-232 communications normally operate well up to a transmission cable
capacitance of 2500 picofarads, or approximately 50 feet of commonly available
serial cable.
• 9-pin RS-232 — 1 DCE port for communicating with a PC through the
supplied serial cable, serial sensors, or through third-party serial
telecommunications devices. Acts as a DTE device with a null-modem cable.
Read More! See the appendix Serial Port Pinouts
(p. 527).
Note The 9-pin RS-232 port is not electrically isolated. "Isolation" means
isolated, by means of optical isolation components, from the communications
node at the other end of the connection. Optical isolation prevents some electrical
problems such as ground looping, which can cause significant errors in single-
ended analog measurements. Campbell Scientific offers a peripheral optically
isolated RS-232 to CS I/O interface as a CR800 accessory. Refer to the appendix
Serial Input / Output Peripherals
(p. 539)
for model information.
• 9-pin CS I/O port: 1 port for communicating through Campbell Scientific
telecommunications peripherals. Approved CS I/O telecommunication
interfaces are listed in the appendix Serial Input / Output Peripherals
(p. 539).
• 2-pin RS-232: 2 ports configurable from control I/O ports for communication
with serial sensors or other Campbell Scientific dataloggers.
5.1.3.6 Integrated Keyboard Display
The integrated keyboard display, illustrated in figure Wiring Panel
(p. 35),
is a
purchased option when buying a CR800 series datalogger. See the appendix
Keyboard Displays
(p. 545)
for more information on available keyboard displays.
The keyboard is an essential installation and maintenance tool for many
applications. It allows interrogation and programming of the CR800 datalogger
independent of other telecommunications links. More information on the use of
the keyboard display is available in the sections Read More! To implement
custom menus, see CRBasic Editor Help for the DisplayMenu() instruction.
CRBasic programming in the CR800 facilitates creation of custom menus for the
external keyboard / display.
Figure Custom Menu Example
(p. 70)
shows windows from a simple custom menu
named DataView. DataView appears as the main menu on the keyboard display.
DataView has menu item Counter, and submenus PanelTemps, TCTemps and
System Menu. Counter allows selection of one of four values. Each submenu
displays two values from CR800 memory. PanelTemps shows the CR800 wiring-