gpib函数

更新时间:2023-05-25 02:08:30 阅读：评论：0

5. GPIB protocol

5.1. GPIB command bytes

The meaning and values of the possible GPIB command bytes are as follows:

Table 12. GPIB command bytes

byte value (hexadecimal)	name	description
0x1	GTL	Go to local
0x4	SDC	Selected device clear
0x5	PPConfig (also 'PPC' on non-powerpc architectures)	Parallel poll configure
0x8	GET	Group execute trigger
0x9	TCT	Take control
0x11	LLO	Local lockout
0x14	DCL	Device clear
0x15	PPU	Parallel poll unconfigure
0x18	SPE	Serial poll enable
0x19	SPD	Serial poll disable
0x20 to 0x3e	MLA0 to MLA30	My (primary) listen address 0 to 30
0x3f	UNL	Unlisten
0x40 to 0x5e	MTA0 to MTA30 送知己	My (primary) talk address 0 to 30
0x5f	UNT	Untalk
0x60 to 0x6f	MSA0 to MSA15, also PPE	When following a talk or listen address, this is 'my condary address' 0 to 15. When following a parallel poll configure, this is 'parallel poll enable'. For parallel poll enable, the least significant 3 bits of the command byte specify which DIO line the device should u to nd its parallel poll respon. The fourth least significant bit (0x8) indicates the 'n' or polarity the device should u when responding.
0x70 to 0x7d	MSA16 to MSA29, also PPD	When following a talk or listen address, this is 'my condary address' 16 to 29. When following a parallel poll configure, this is 'parallel poll disable'.
0x7e	MSA30	My condary address 30

5.2. GPIB bus lines

Physically, the GPIB bus consists of 8 data lines, 3 handshaking lines, and 5 control lines (and 8 ground lines). Brief descriptions of how they are ud follow:

Table 13. GPIB bus lines

迪玛希个人资料简介有关数学的故事

bus line	宁济 description	pin number
DIO1 through DIO8	Data input/output bits. The 8 lines are ud to read and write the 8 bits of a data or command byte that is being nt over the bus.	DIO1 to DIO4 u pins 1 to 4, DIO5 to DIO8 u pins 13 to 16
EOI	End-or-identify. This line is asrted with the last byte of data during a write, to indicate the end of the message. It can also be asrted along with the ATN line to conduct a parallel poll.	5
DAV	Data valid. This is a handshaking line, ud to signal that the value being nt with DIO1-DIO8 is valid. During transfers the DIO1-DIO8 lines are t, then the DAV line is asrted after a delay called the 'T1 delay'. The T1 delay lets the data lines ttle to stable values before they are read.	6
NRFD	Not ready for data. NRFD is a handshaking line asrted by listeners to indicate they are not ready to receive a new data byte.	7 男士护肤品排行榜
NDAC	Not data accepted. NDAC is a handshaking line asrted by listeners to indicate they have not yet read the byte contained on the DIO lines.白内障的主要症状是什么	8
IFC	Interface clear. The system controller can asrt this line (it should be asrted for at least 100 microconds) to ret the bus and make itlf controller-in-charge.	9
SRQ	Service request. Devices on the bus can asrt this line to request rvice from the controller-in-charge. The controller can then poll the devices until it finds the device requesting rvice, and perform whatever action is necessary.	10
ATN	Attention. ATN is asrted to indicate that the DIO lines contain a command byte (as oppod to a data byte). Also, it is asrted with EOI when conducting parallel polls.	11
REN	Remote enable. Asrted by the system controller, it enables devices to enter remote mode. When REN is asrted, a device will enter remote mode when it is addresd by the controller. When REN is fal, all devices will immediately return to local mode.	17
食用油十大品牌>电话话术

ibwrt

Name

ibwrt -- write data bytes (board or device)

Synopsis

class=FUNCSYNOPSISINFO

#include <gpib/ib.h>

int ibwrt(int ud, const void *data, long num_bytes);

Description

ibwrt() is ud to write data bytes to a device or board. The argument ud can be either a device or board descriptor. num_bytes specifies how many bytes are written from the ur-supplied array data. EOI may be asrted with the last byte nt or when the end-of-string character is nt (e ibeos() and ibeot()). The write operation may be interrupted by a timeout (e ibtmo()), the board receiving a device clear command, or receiving an interface clear.

If ud is a device descriptor, then the library automatically handles addressing the device as listener and the interface board as talker, before nding the data bytes onto the bus.

If ud is a board descriptor, the board simply writes the data onto the bus. The controller-in-charge must address the board as talker.

After the ibwrt() call, ibcnt and ibcntl are t to the number of bytes written.

Return value

The value of ibsta is returned.

ibdev

Name

ibdev -- open a device (device)

Synopsis

class=FUNCSYNOPSISINFO#include <gp

ib/ib.h>

int ibdev(int board_index, int pad, int sad, int timeout, int nd_eoi, int eos);

Description

ibdev() is ud to obtain a device descriptor, which can then be ud by other functions in

the library. The argument board_index specifies which GPIB interface board the device is connected to. The pad and sad arguments specify the GPIB address of the device to be opened (e ibpad() and ibsad()). The timeout for io operations is specified by timeout (e ibtmo()). If nd_eoi is nonzero, then the EOI line will be asrted with the last byte nt during writes (e ibeot()). Finally, the eos argument specifies the end-of-string character and whether or not its reception should terminate reads (e ibeos()).

本文发布于:2023-05-25 02:08:30，感谢您对本站的认可！

本文链接：https://www.wtabcd.cn/fanwen/fan/89/927520.html

上一篇：APX809_APX810

下一篇：MAX6409BS36-T中文资料

标签：电话品牌男士有关简介白内障

留言与评论（共有 0 条评论）