Lake Shore Model 475 Gaussmeter User’s Manual
Remote Operation
6-7
6.1.4.1.5 Reading Registers
Any register in the status system may be read using the appropriate query command. Some registers clear when read,
others do not. Refer to Paragraph 6.1.4.1.7. The response to a query will be a decimal value which corresponds to the
binary-weighted sum of all bits in the register, refer to Table 6-1. The actual query commands are described later in this
section.
Table 6-1. Binary Weighting of an 8-Bit Register
Position
B7
B6
B5
B4
B3
B2
B1
B0
Decimal
128
64
32
16
8
4
2
1
Weighting
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
Example: If bits 0, 2, and 4 are set, a query of the register will return a decimal value of 21 (1+4+16).
6.1.4.1.6 Programming Registers
The only registers that may be programmed by the user are the enable registers. All other registers in the status system
are read-only registers. To program an enable register send a decimal value which corresponds to the desired binary-
weighted sum of all bits in the register, refer to Table 6-1. The actual commands are described later in this section.
6.1.4.1.7 Clearing Registers
The methods to clear each register are detailed in Table 6-2.
Table 6-2. Register Clear Methods
Register
Method
Example
Condition Registers
None – registers are not latched
Event Registers
Standard Event Status Register
Operation Event Register
Query the event register.
*ESR?
(clears Standard Event Status
register)
Send *CLS
*CLS
(clears both registers)
Power on instrument
Enable Registers:
Standard Event Status Enable
Register
Operation Event Enable Register
Service Request Enable Register
Write 0 to the enable register.
*ESE 0
(clears Standard Event Status
Enable register)
Power on instrument
Status Byte
There are no commands that directly clear the
Status Byte as the bits are non-latching. To
clear individual summary bits, clear the event
register that corresponds to the summary bit.
Sending *CLS will clear all event registers
which in turn clears the status byte.
If bit 5 (ESB) of the Status
Byte is set, send *ESR? to read
the Standard Event Status
Register and bit 5 will clear.
Power on instrument
