CR10 OVERVIEW

Table 1.

Execute every x sec. 0.0156 < x < 8191

Instructions are executed sequentially in the order they are entered in the table. One complete pass through the table is made each execution interval unless program control instructions are used to loop or branch execution.

Normal Order:

MEASURE

PROCESS

CHECK OUTPUT COND. OUTPUT PROCESSING

Table 2.

Execute every y sec. 0.0156 < y < 8191

Table 2 is used if there is a need to measure and process data on a separate interval from that in Table 1.

Table 3.

Subroutines

A subroutine is executed only when called from Table 1 or 2.

Subroutine Label

Instructions

End

Subroutine Label

Instructions

End

Subroutine Label

Instructions

End

FIGURE OV2.3-1. Program and Subroutine Tables

Each instruction in the table requires a finite time to execute. If the execution interval is less than the time required to process the table, an execution interval overrun occurs; the CR10 finishes processing the table and waits for the next execution interval before initiating the table. When an overrun occurs, decimal points are shown on either side of the G on the display in the LOG mode (*0). Overruns and table priority are discussed in Section 1.1.

OV2.3.2. THE OUTPUT INTERVAL

The interval at which output occurs is independent from the execution interval, other than the fact that it must occur when the table is executed (e.g., a table cannot have a 10 minute execution interval and output every 15 minutes).

A single program table can have many different output intervals and conditions, each with a unique data set (Output Array). Program Control Instructions are used to set the Output Flag. The Output Processing Instructions which follow the instruction setting the Output Flag determine the data output and its sequence. Each additional Output Array is created by another Program Control Instruction checking a output condition, followed by Output Processing Instructions defining the data set to output.

OV-10

OV3. COMMUNICATING WITH CR10

An external device must be connected to the CR10's Serial I/O port to communicate with the CR10. This may be either Campbell Scientific's portable CR10KD Keyboard Display or a computer/terminal.

The CR10KD is powered by the CR10 and connects directly to the serial port via the SC12 cable (supplied with the CR10KD). No interfacing software is required.

To communicate with any device other than the CR10KD, the CR10 enters its Telecommunications Mode and responds only to valid telecommunications commands. Within the Telecommunications Mode, there are 2 "states"; the Telecommunications Command state and the Remote Keyboard state. Communication is established in the Telecommunications command state. One of the commands is to enter the Remote Keyboard state.

The Remote Keyboard state allows the keyboard of the computer/terminal to act like the CR10KD keyboard. Various datalogger modes may be entered, including the mode in which programs may be keyed in to the CR10 from the computer/terminal.

Campbell Scientific's PC208 Datalogger Support Software facilitates the use of IBM PC/XT/AT/PS-2's and compatibles for communicating with the CR10. This package