电脑接上gprs modem后可以发短信，但拨号上网失败？
win2k系统，接上usb gprs modem后可以用短信软件收发短信，但拨号上网老是失败，用bus hound抓usb数据，出现状态为：usts Pid chk fail
请教这是什么原因？pid chk fail又是什么意思？
谢谢！
问题点数：0、回复次数：4Top
1 楼klbt（快乐白兔）回复于 2003-09-03 20:22:44 得分 0
奇怪的问题，顶。Top
2 楼dwkang（方煷）回复于 2003-09-04 11:49:50 得分 0
发邮件给bus hound得到的回复是：
The error you are getting is defined by Microsoft and the full name is USBD_STATUS_PID_CHECK_FAILURE. This is a hardware related failure. The error indicates the packet ID (PID) which contains a check field was corrupt making the packet invalid. See below excerpt from the USB 2.0 spec. If you need further information, you could ask about this error under the www.usb.org developer forum, usenet, or Microsoft. Hope that helps
但在微软的网站上并没有pcd chk fail的信息，在usb2.0协议的8.3.1有pid相关定义：
8.3.1 Packet Identifier Field
A packet identifier (PID) immediately follows the SYNC field of every USB packet. A PID consists of a
four-bit packet type field followed by a four-bit check field as shown in Figure 8-1. The PID indicates the
type of packet and, by inference, the format of the packet and the type of error detection applied to the
packet. The four-bit check field of the PID ensures reliable decoding of the PID so that the remainder of the
packet is interpreted correctly. The PID check field is generated by performing a one’s complement of the
packet type field. A PID error exists if the four PID check bits are not complements of their respective
packet identifier bits.
(MSb) (LSb)
PID 2 PID 3 PID 1 0
PID PID 0 PID 1 PID
2
PID 3
Figure 8-1. PID Format
The host and all functions must perform a complete decoding of all received PID fields. Any PID received
with a failed check field or which decodes to a non-defined value is assumed to be corrupted and it, as well
但我仍然没有头绪，各位帮帮忙啊！！！
谢谢Top
3 楼wxxzf（小风）回复于 2003-12-24 11:44:09 得分 0
把传输速度改慢点看看Top
4 楼guangqiangliu（crystal）回复于 2003-12-24 13:21:34 得分 0
恩你在现在的状态再建一个连接看看可以不Top
