Measurement-computing Micro 488/EX rev.2.1 Manual de usuario descargar pdf (Pagina 147)

Section 5 Command Descriptions

5.77

SPOLL

In Active Controller mode the

SPOLL

command performs a Serial Poll of the bus

device specified and responds with number from

255

representing the decimal

equivalent of the eight-bit device response. If

rsv

(DIO7, decimal value 64) is set, then

that device is signaling that it requires service. The meanings of the other bits are

device-specific. Serial Polls are normally performed in response to assertion of the

Service Request (SRQ) bus signal by some bus device. If multiple addresses are

specified, the Micro488/EX will serial poll each device in sequence and output each

device's response to the serial port with the serial output terminator(s) appended.

In Active Controller mode, with no bus address specified, the

SPOLL

command

returns the external SRQ status. If the SRQ line is asserted, the Micro488/EX will

return a "64". If it is not asserted, the Micro488/EX will return a "0".

In Peripheral mode the

SPOLL

command is issued without an address and returns

Macro488's own serial poll status. If

rsv

(DIO7, decimal value 64) is set, then the

Micro488/EX has not been Serial Polled since the issuing last

REQUEST

command.

rsv

is reset whenever the Micro488/EX is Serial Polled by the Controller.

SYNTAX SPOLL

[addr[,addr…]]

addr is the bus device(s) to be Serial Polled

RESPONSE 0 or 64 (without

addr

)

0 to 255 (with

addr

)

MODE CA

BUS STATES ATN•UNL, MLA, TAG, SPE, *ATN, data, ATN•SPD, UNT

EXAMPLES

PRINT#1,"SPOLL 16"

Serial Poll device 16

INPUT#1,SPSTAT

Receive the Spoll status

IF SPSTAT AND 64 THEN…

Test

rsv

…

1 2 ... 142 143 144 145 146 147 148 149 150 151 152 ... 217 218

Comentarios a estos manuales

Sin comentarios

Measurement-computing Micro 488/EX rev.2.1 Manual de usuario Pagina 147

Comentarios a estos manuales

Relacionado con productos y manuales para Hardware Measurement-computing Micro 488/EX rev.2.1