Lake Shore 625, Руководство пользователя

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Lake Shore Model 625 Superconducting MPS User’s Manual
Computer Interface Operation 5-7
5.1.4.1.6 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 5.1.4.1.7. The response to a query will be a decimal value that corresponds to the
binary-weighted sum of all bits in the register, see Table 5-1. The actual query commands are described later in this
section.
Table 5-1. 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).
5.1.4.1.7 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, see Table 5-1. The actual commands are described later in this section.
5.1.4.1.8 Clearing Registers
The methods to clear each register are detailed below.
Table 5-2. Register Clear Methods
Register Method Example
Condition Registers None – registers are not latched
—
Event Registers
Standard Event Status Register
Operation Event Register
Error Status 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
Error Status 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
—