信息的传送口线有串口和并口之分:通常的PLC是8位机,当然也有16位机。我们在发送数据的时候可以是一位一位的发送给对方,也可以8位8位的将数据发送到对方,一位和8位区别也就是我们所说的串口发送数据和并口发送数据。串口速度比较慢,但只要两条或者三条口线就能解决问题,并能借用电话线来进行远程控制。而并口的传送速度是极快的,它是串口的256倍,在短距离占有优势,由于是TTL电平,一般限于1米的范围,它并不适用于长距离的数据传送,这样成本太昂贵了。
当你在看书的时候,你听到有人敲门、你停下手上的事情、去打开门、并同敲门者对话、这个时候电话响了、你示意接个电话、在接完电话后、回过头来同敲门者继续对话、对话完毕后、你再继续看你的书,这种情况我们把它称为中断,它具有权威,也具有优先,PLC具备了这样的功能。它的特点在于我们在设备的操作过程中可能会遇到紧急的突发事件,我们要立刻的停下手上的工作,去处理更重要的事情,这种情况是我们经常所遇到的,PLC在去执行紧急的任务时,总会先保存目前的状态,比如程序的地址,的累加器数据等,就像我们去开门时要记下我们看的书在第几页了或者干脆作个记号,因为我们待会还要继续接着看后面的书。总是按照我们的意愿去做应该做的事情,但你错误的给它一件事情,它也会同样的去做,这一点我们必须注意。
中断并不是只有一个,有时会同时存在几个中断,中断具有优先的级别,他们会根据人的要求去执行更别的中断。这种中断中的中断也就形成了中断嵌套。当然中断的级别根据各种PLC内部的资源有关,同时也跟堆栈的容量大小也有关系。
中断的内容有很多种,比如外部中断、通信中的发送和接受中断、定时和计数的时钟中断、还有WDT复位中断等,它们丰富了在处理各种事务时响应种类。这样讲也许你并不能完全理解中断的内部结构和操作顺序,我们做一个小小的例子来说明.
每一个设备总是不会忘记有一个按钮,它也是在我们遇到紧急情况时使用的,那就是急停按钮。当我们遇到人身事故和意外情况时我们只要按下它,机器立即停止所有的操作,并等待处理完意外后再恢复操作。急停按钮连接PLC内部的内部I/O接口上,当按钮给一个外部触发信号时,对I/O进行再次检测,当确认有外部触发信号时,保护现场并将程序计数器自动转到相应的外部I/O中断程序中去,当外部中断程序处理完毕,程序计数器返回到主程序继续工作。有一点可以说明的是我们一般会把急停按钮的外部中断升至别,从而保证安全。
当我们在工作完一个工件时,给PLC一个信号,将PLC的内部计数器加1来计算我们的工作量时,一个简单的计数器能解决问题,当然它们也能够在掉电的情况下保持数据,促使数据不丢失,这也是我们所渴望的。
PLC还具有计数器的功能,当我们在接受一些高速的数据时,这里所说的高速是在在微秒级的数据,比如条码扫描机在不断的扫描数据,数据处理器DSP计算的高速信号等,我们就要采用到计数器来帮助我们进行计数。它在PLC执行程序时一旦发现计数器对应的中断,就会立即放下手上的工作。经过再次编程的梯形图程序说明我们在执行程序时计数器会自动的执行对应的工作,从而将计数器的级别升至高一级别。
MVME147S
MVME147S-1
MVME147SA
MVME147SA-1
MVME147SA-2
MVME147SB-1
MVME147SB-2
MVME147SC-1
MVME147SC-2
MVME147SRF
MVME147-010
MVME147-011
MVME147-011A
MVME147-012
MVME147-012A
MVME147-013
MVME147-013A
MVME147-014
MVME147-014A
MVME147-022
MVME147-022A
MVME147-023
MVME147-023A
MVME147-024
MVME147-024A
MVME148
MVME148-001
MVME162-001
MVME162-002
MVME162-003
MVME162-010
MVME162-010A
MVME162-011A
MVME162-012
MVME162-012A
MVME162-013
MVME162-013A
MVME162-014A
MVME162-020
MVME162-020A
MVME162-021A
MVME162-022
MVME162-022A
MVME162-023
MVME162-023A
MVME162-026A
MVME162-030
MVME162-031
MVME162-032
MVME162-033
MVME162-040
MVME162-041
MVME162-042
MVME162-043
MVME162-200
MVME162-201
MVME162-202
MVME162-210
MVME162-211
MVME162-212
MVME162-213
MVME162-216
MVME162-220
MVME162-222
MVME162-223
MVME162-233
MVME162-243
MVME162-253
MVME162-262
MVME162-263
MVME162-322
MVME162-323
MVME162-333
MVME162-353
MVME162-403
MVME162-410
MVME162-411
MVME162-412
MVME162-413
MVME162-430
MVME162-431
MVME162-432
MVME162-433
MVME162-453
MVME162-510A
MVME162-511A
MVME162-512
MVME162-512A
MVME162-513
MVME162-513A
MVME162-520A
MVME162-521A
MVME162-522
MVME162-522A
MVME162-523
MVME162-523A
MVME162-530A
MVME162-531A
MVME162-532
MVME162-532A
MVME162-533
MVME162-533A
MVME162-723
MVME162-743
MVME162-763
MVME162-813
MVME162-833
MVME162-853
MVME162-863
MVME162P-242
MVME162P-242E
MVME162PA-242
MVME162PA-242E
MVME162P-242L
MVME162PA-242L
MVME162P-244LE
MVME162P-242LE
MVME162PA-242LE
MVME162PA-242LNS
MVME162P-242SE
MVME162PA-242SE
MVME162P-244L
MVME162PA-244L
MVME162PA-244LE
MVME162PA-244LN
MVME162P-242LSE
MVME162PA-242LSE
MVME162P-244LSE
MVME162PA-244LSE
MVME162PA-252LSE
MVME162P-252SE
MVME162PA-252SE
MVME162P-344
MVME162PA-344
MVME162P-344E
MVME162PA-344E
MVME162P-344S
MVME162PA-344S
MVME162P-344SE
MVME162PA-344SE
MEM162
MVME162-013 MVME333-2 MVME167-031A? MVME177-003 PMC243MOT-R40M?
MVME162-013A? MVME374 MVME167-032B? MVME177-004 MVME162-523
MVME162-020 MVME374-1 MVME167-033A? MVME177-005 MVME162-532A
MVME162-022? MVME376 MVME167-033B? MVME177-006 MVME162P-242LE
MVME162-023? MVME705-1 MVME167-034A MVME177-012 MVME162P-242LSE
MVME162-023A? MVME705A MVME167-34B? MVME177-013 MVME162P-244LE
MVME162-032 MVME705A w/RFI MVME167-034B? MVME177-014 MVME162P-252SE
MVME162-040? MVME705A-001 MVME167-035B? MVME177-015 MVME162P-344
MVME162-211 MVME705B w/RFI MVME167-036B? MVME177-016 MVME162P-344E
MVME162-212 MVME708-001 MVME167P-036SE MVME177P-54SE MVME162PA-242LE
MVME162-213 MVME710B MVME167P-35SE? MVME177P-55SE MVME162PA-244L
MVME162-215 MVME721-101 MVME167P-34SE? MVME177P-56SE MVME162PA-244LE
MVME162-222 MVME712-103 MVME167-04? MVME177P-64SE MVME162PA-244LSE
MVME162-223 MVME712-104 MVME167A MVME177P-65SE MVME162PA-344B
MVME162-253 MVME712A MVME167C MVME177P-66SE MVME162PA-344E
MVME162-263 MVME712/AM MVME167P-24SE MVME177P-67SE MVME162-512A
MVME162-410 MVME712B MVME167P-35SE MVME162-512A MVME162-433
MVME162-412 MVME712M MVME761-001 MVME162-522A MVME162-510A
MVME162-432 MVME712/M MVME761EXT MVME714
MVME162-013 MVME333-2 MVME167-031A? MVME177-003 PMC243MOT-R40M?
MVME162-013A? MVME374 MVME167-032B? MVME177-004 MVME162-523
MVME162-020 MVME374-1 MVME167-033A? MVME177-005 MVME162-532A
MVME162-022? MVME376 MVME167-033B? MVME177-006 MVME162P-242LE
MVME162-023? MVME705-1 MVME167-034A MVME177-012 MVME162P-242LSE
MVME162-023A? MVME705A MVME167-34B? MVME177-013 MVME162P-244LE
MVME162-032 MVME705A w/RFI MVME167-034B? MVME177-014 MVME162P-252SE
MVME162-040? MVME705A-001 MVME167-035B? MVME177-015 MVME162P-344
MVME162-211 MVME705B w/RFI MVME167-036B? MVME177-016 MVME162P-344E
MVME162-212 MVME708-001 MVME167P-036SE MVME177P-54SE MVME162PA-242LE
MVME162-213 MVME710B MVME167P-35SE? MVME177P-55SE MVME162PA-244L
MVME162-215 MVME721-101 MVME167P-34SE? MVME177P-56SE MVME162PA-244LE
MVME162-222 MVME712-103 MVME167-04? MVME177P-64SE MVME162PA-244LSE
MVME162-223 MVME712-104 MVME167A MVME177P-65SE MVME162PA-344B
MVME162-253 MVME712A MVME167C MVME177P-66SE MVME162PA-344E
MVME162-263 MVME712/AM MVME167P-24SE MVME177P-67SE MVME162-512A
MVME162-410 MVME712B MVME167P-35SE MVME162-512A MVME162-433
MVME162-412 MVME712M MVME761-001 MVME162-522A MVME162-510A