Stop bit problem: USB to Serial Converter attached to motion controller, unable to set for 7-E-2

pts.
Tags:
3Com
Active Directory
ActiveX
Administration
Apache
Automation
Availability
BASIC
Benchmarking
Business Objects
C
Cabling
Cape Clear Cape Connect
Career Development
Cisco
Clustering
Cognos
Crystal Reports
Data analysis
Data Junction
Data management and storage
Data Mining
Data warehousing applications
Database
DataCenter
Dell
Desktop management applications
Development
DHCP
Distribution/logistics applications
DNS
Enterprise Desktop
Ethernet
Fault isolation
Fax and print management
FDDI
File
Frame Relay
Functional
H.323
Hardware
Hewlett-Packard
Hewlett-Packard Application Server
Hubs
Hyperion
IBM
IBM DB2
Informatica
Information Builders
Interoperability
Lifecycle development
Linux
Lotus Domino
Management
Manufacturing applications
Microprocessors
Microsoft Systems Management Server
Microsoft Windows
Migration
Monitoring
NCR
Network applications management
Network connectivity
Network management software
Network monitoring
Network protocols
Network testing
Networking
Networking services
NIC
Novell IPX/SPX
Oracle
OS
Performance and availability
Performance management
Performance/Load
Ping
Power management
Printers
Programming Languages
Protocol analysis
Remote management
Routers
SAP
SAS Institute
Security
Servers
Software
Software testing
Software testing tools
SPSS
SQL Server
standards
Storage
Switches
Systems management software
TCP
Thermal controls
I have three different USB to Serial converters, one of them an isolated converter from B&B. One brand of motion controller I work on uses EVEN parity / 7 data bits / 2 stop bits as its default. I find that none of my converters will work on the controller in this configuration. If I borrow a PC with a fixed serial port and change the comm setup to use 1 stop bit, I can then connect using my USB converters. What is there about the 2 stop bit setup that prevents my USB converters from working? I acknowledge 2 stop bits is rare, but TRIO Motion Technology uses it as their standard default (don't know why). This has meant that every time I've been called to work on one of them, I've had to borrow a laptop with a fixed port. I've never attempted configuring my PC for E-7-1 while leaving the motion controller at E-7-2. I'll try that the next time. I'm curious as to why PC's with fixed serial ports handle the 2 stop bits OK, but the USB ports don't. Any idea?

Answer Wiki

Thanks. We'll let you know when a new response is added.

This may seem like a silly response, but since the 7-E-2 setting is the default, can it be changed? While I find dealing with serial communications on PLCs to be a pain in the butt, I’ve never had to deal with odd settings like that one.

Good luck!

Discuss This Question: 2  Replies

 
There was an error processing your information. Please try again later.
Thanks. We'll let you know when a new response is added.
Send me notifications when members answer or reply to this question.

REGISTER or login:

Forgot Password?
By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy
  • Paul144hart
    This is something the USB manufacturer would have to look at. It may be the chip actually doing the serial I/O on the adapter is too picky. Usually the clash would be a device sending bytes with one stop bit to something that thinks it will have two could cause a problem. The RS232 ports (real ones) use UARTs that are forgiving. If the adapter is using a CPU like a 8051 they may conform more rigorously to the spec.
    0 pointsBadges:
    report
  • BenjiT
    Why would you post this on a message board for database systems...specifically SQL Server?
    0 pointsBadges:
    report

Forgot Password

No problem! Submit your e-mail address below. We'll send you an e-mail containing your password.

Your password has been sent to:

To follow this tag...

There was an error processing your information. Please try again later.

REGISTER or login:

Forgot Password?
By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

Thanks! We'll email you when relevant content is added and updated.

Following