Campbell Manufacturing CR10 NOTE, Range Code, Resolution, Full Scale Range, 3.6 OUTPUT PROCESSING, SECTION 3. INSTRUCTION SET BASICS, 3.5VOLTAGE RANGE AND OVERRANGE DETECTION

SECTION 3. INSTRUCTION SET BASICS

Location or Port the instruction acts on. Normally the loop counter is incremented by 1 after each pass through the loop. Instruction 90, Step Loop Index, allows the increment step to be changed. See Instructions 87 and 90, Section 12, for more details.

To index an input location (4 digit integer) or set port command (2 digit integer) parameter, C or "-" is pressed after keying the value but before entering the parameter. Two minus signs (-) will be displayed to the right of the parameter.

3.5VOLTAGE RANGE AND OVERRANGE DETECTION

The voltage RANGE code parameter on Input/Output Instructions is used to specify the full scale range of the measurement and the integration period for the measurement (Table 3.5-1).

The full scale range selected should be the smallest that will accommodate the full scale output of the sensor being measured. Using the smallest possible range will result in the best resolution for the measurement.

Four different integration sequences are possible. The relative immunity of the integration sequences to random noise is: 60 Hz rej. = 50 Hz rej. > 2.72ms integ. > 272 ∝s integ. The 60 Hz rejection integration rejects noise from 60 Hz AC line power. The 50 Hz rejection is for countries whose electric utilities operate at 50 Hz (Section 13.1).

When a voltage input exceeds the range programmed, the value which is stored is set to the maximum negative number and displayed as -99999 in high resolution or -6999 in low resolution.

An input voltage greater than +5 volts on one of the analog inputs will result in errors and possible overranging on the other analog inputs. Voltages greater than 16 volts may permanently damage the CR10.

NOTE: Voltages in excess of 5.5 volts applied to a control port can cause the CR10 to malfunction.

3.6 OUTPUT PROCESSING

Most Output Processing Instructions require both an Intermediate Data Processing operation and a Final Data Processing operation. For example, when the Average Instruction, 71, is initiated, the intermediate processing operation increments a sample count and adds each new Input Storage value to a cumulative total residing in Intermediate Storage. When the Output Flag is set, the final processing operation divides the cumulative total by the number of samples to find the average. The average is then stored in final storage and the cumulative total and number of samples are set to zero in Intermediate Storage.

Final Storage Area 1 (Sections 1.5, 2.1) is the default destination of data output by Output Processing Instructions. Instruction 80 may be used to direct output to either Final Storage Area 2 or to Input Storage.

Output Processing Instructions requiring intermediate processing sample the specified input location(s) each time the Output Instruction is executed, NOT each time the location value is updated by an I/O Instruction. For example: Suppose a temperature measurement is initiated by Table 1 which has an execution interval of 1 second.

		TABLE 3.5-1. Input Voltage Ranges and Codes
	Range Code		Full Scale Range	Resolution*
Slow	Fast
2.72ms	250 us	60 Hz	50 Hz
Integ.	Integ.	Reject.	Reject.

1	11	21	31	±2.5 mV		0.33	µV
2	12	22	32	±7.5 mV		1.	µV
3	13	23	33	±25	mV	3.33	µV
4	14	24	34	±250	mV	33.3	µV
5	15	25	35	±2500	mV	333.	µV

*Differential measurement, resolution for single-ended measurement is twice value shown.

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