Tektronix MTD200, Руководство пользователя

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Remote Control
5–58
MTD200 MPEG Test Decoder User Manual
The connection between the MTD200 and the controller must be made using
a null modem cable.
Follow the instructions that are supplied with your RS-232 control program.
Examples (see also Figure 5–3 on page 5–49 and Program Examples on
page 5–68):
1. Using the command *OPC to generate an SRQs:
a. Set bit 0 (Operation Complete) in the ESE.
b. Set bit 5 (ESB) in the SRE.
The instrument generates an SRQ upon completion of its settings.
2. Indicating the end of a measurement by an SRQ on the controller
a. Set bit 7 (summary bit of the STATus:OPERation register) in the SRE.
b. Set bit 4 (MEASuring) in the STATus:OPERation:ENABle register.
c. Set bit 4 in the STATus:OPERation:NTRansition register so that the
transition of the MEASuring bit from 1 to 0 (measure end) will also be
noted in the EVENt register.
After having provided a stable measured value, the instrument generates an
SRQ.
The SRQ is the only way for the instrument to become active on its own. A
controller program should set the instrument so that a service request will be
generated in case of malfunctions. The program should suitably respond to the
service request.
Queries. Each individual register of a status register can be read out by queries.
The individual queries are discussed in Description of Status Registers on
page 5–53. The queries always return a number representing the bit pattern of the
queried register. This number is evaluated by the controller program.
Queries to read out the status registers are mainly used after an SRQ to obtain
detailed information on the cause for the SRQ.