Keithley 2500 User Manual

Models 2500 and 2502 User’s Manual Status Structure 14-5
Programming and reading registers
Programming enable registers
The only registers that can be programmed by the user are the enable registers. All other
registers in the status structure are read-only registers. The following explains how to
ascertain the parameter values for the various commands used to program enable registers.
The actual commands are covered later in this section (Table 14-3 and Table 14-6).
A command to program an event enable register is sent with a parameter value that deter-
mines the desired state (0 or 1) of each bit in the appropriate register. An enable register
can be programmed using any of the following data formats for the parameter value:
binary, decimal, hexadecimal, or octal.
The bit positions of the register (Figure 14-2) indicate the binary parameter value. For
example, if you wish to set bits B4, B3, and B1, the binary value would be 11010 (where
B4=1, B3=1, B1=1, and all other bits are 0). When you use one of the other formats, con-
vert the binary number to its decimal, hexadecimal, or octal equivalent:
Binary 11010 = Decimal 26 = Hexadecimal 1A = Octal 32
Note that Figure 14-2 includes the decimal weight for each register bit. To set bits B4, B3,
and B1, the decimal parameter value would be the sum of the decimal weights for those
bits (16+8+2 = 26).
Figure 14-2
16-bit status register
The <NDN> (non-decimal numeric) parameter type is used to send non-decimal values.
These values require a header (#B, #H, or #Q) to identify the data format being sent. The
letter in the header can be upper or lower case. The <NRf> (numeric representation
(2
7
)(2
6
)(2
5
)(2
4
)(2
3
)
(2
2
)
(2
1
)(2
0
)
(2
15
)(2
14
)
(2
13
)(2
12
)(2
11
)(2
10
)(2
9
)(2
8
)
Bit Position
Binary Value
Decimal
Weights
B7
B6
B5
B4
B3
B2
B1 B0
0/1
0/1 0/10/1 0/1 0/10/10/1
128
64
32
16
8 4
2
1
B15 B14 B13 B12 B11 B10 B9 B8
32768
16384
8192
4096 2048 1024 512 256
0/1
0/1 0/10/1 0/1 0/10/10/1
Bit Position
Binary Value
Decimal
Weights
B. Bits 8 through 15
A. Bits 0 through 7
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Keithley 2500 Specifications

General

Brand	Keithley
Model	2500
Category	Measuring Instruments
Language	English