Benchtop Measurement and Test
Distributed Measurement and Control
High-Performance Test
Systems Engineering Software
Perspectives showcases how NI sees what’s next in the world of test and technology.
You can request repair, RMA, schedule calibration, or get technical support. A valid service agreement may be required.
Provides support for NI data acquisition and signal conditioning devices.
Provides support for Ethernet, GPIB, serial, USB, and other types of instruments.
Provides support for NI GPIB controllers and NI embedded controllers with GPIB ports.
From Friday, April 19th (11:00 PM CDT) through Saturday, April 20th (2:00 PM CDT), 2024, ni.com will undergo system upgrades that may result in temporary service interruption.
We appreciate your patience as we improve our online experience.
10-07-2011 03:25 AM
想让施耐德plc作为从站 上位机编写通讯程序读取plc里面的数据 在施耐德自带的《使用技巧文集》里面有一个例子 是用VB实现MODBUS串行通讯的 如图 我理解其中的%MW10就是对应地址0010 我用自己编写的程序读取其中的数据 用总是出现错误-1073807253 我也设置了延时和VISA CLEAR 仍然不能解决问题 我不知道自己是哪里错了 希望各位大神帮忙
10-08-2011 08:57 AM
assert the RTS line before writing, then after the writing, delay by several ms and the de-assert the line.
RTS line的设置如下:
10-09-2011 08:59 PM
我按照您说的改了以后,什么数据也读不出来,不知道你说的这个设置是什么意思
10-09-2011 10:03 PM
通信过程中,有些时候存在着RTS设置问题时会出现传输错误的情况;
此外,还可能是您帧结构出现了问题,请参考下列链接:
http://forums.ni.com/t5/NI-LabVIEW-CVI-%E6%95%B0%E6%8D%AE%E9%87%87%E9%9B%86%E7%AD%89%E4%BA%A7%E5%93%...
10-11-2011 02:37 AM
谢谢您的解答 我会再研究一下帧结构的
12-13-2013 02:39 AM
我用的是MODBUS指令,与M238通过499网络模块通讯,但是总是会出现问题,程序如图,第一幅图是modbus指令VI,在第二幅图中调用,在这个程序中,我连接了3个PLC,两个是施耐德的M258,自带以太网接口,一个M238,不带以太网接口,扩展一个以太网模块499, 但是与M258通讯时正常,一运行到与M238的499通讯时,就会出现以上错误。请指教,参数哪里错了。
What do you need our team of experts to assist you with?
Thanks!
We'll be in touch soon!