Member Login
Search
Jump to a Date
Sponsored Communities
Cool stuff
Twitter Feed
Neat Stuff

Visit our shop for nerds in control lifestyle products.
Thermal Overload
The threads that wouldn't die...
- PC reliability?
- Windows, real time
- PID loops
- PCs vs. PLCs
- Replacing people
- MS 'monopoly'?
- Software quality
- Where do we go from here?
- Why pay?
- PC reliability?
- Windows, real time
- PID loops
- PCs vs. PLCs
- Replacing people
- MS 'monopoly'?
- Software quality
- Where do we go from here?
- Why pay?
Fortune
A dozen, a gross, and a score,
Plus three times the square root of four,
Divided by seven,
Plus five times eleven,
Equals nine squared plus zero, no more.
Plus three times the square root of four,
Divided by seven,
Plus five times eleven,
Equals nine squared plus zero, no more.
RSS Feed
www.control.com/rss/
To get a personalized feed, become a member at no cost.
I need two Modbus master hosts to communicate with one Modbus slave.
Current (one master, one slave):
MBMaster1<-->MBSlave
Desired (two master, one slave):
MBMaster1<-->|--------|
|BlackBox|<-->MBSlave
MBMaster2<-->|--------|
De tails:
MBSlave has a RS485 that's converted to RS232
MBMaster1 has a RS232
MBMaster2 has a RS232
MBSlave does not support handshaking/flow-control
MBMaster1 and MBMaster2 are independent, so 'may' send request to MBSlave at random/same time.
Questions:
What do I have to do beforehand for this to work?
What kind of 'black box' solution do I need to buy?
Thank you,
jmczero @ hotmail. com
Current (one master, one slave):
MBMaster1<-->MBSlave
Desired (two master, one slave):
MBMaster1<-->|--------|
|BlackBox|<-->MBSlave
MBMaster2<-->|--------|
De tails:
MBSlave has a RS485 that's converted to RS232
MBMaster1 has a RS232
MBMaster2 has a RS232
MBSlave does not support handshaking/flow-control
MBMaster1 and MBMaster2 are independent, so 'may' send request to MBSlave at random/same time.
Questions:
What do I have to do beforehand for this to work?
What kind of 'black box' solution do I need to buy?
Thank you,
jmczero @ hotmail. com
Our product, the XLTR-200 serial gateway, has 2 RS485 ports and one RS232 port, each of which can be independently configured as Modbus Master or Modbus Slave ports. It is frequently used to allow 2 master devices to simultaneously access one or more slave devices.
http://iccdesigns.com/Merchant2/merchant.mv?Screen=PRO D&Store_Code=ICC&Product_Code=xltr200
Regards,
Darrin Hansen
ICC, Inc.
http://iccdesigns.com/Merchant2/merchant.mv?Screen=PRO D&Store_Code=ICC&Product_Code=xltr200
Regards,
Darrin Hansen
ICC, Inc.
Jmc,
One system I am aware of that will fit your needs is the PLC09 Modbus Arbitrator from Calta Computer Systems Limited.
http://www.calta.com/
This unit will allow up to three masters to poll a single Modbus slave.
Ian Milne
One system I am aware of that will fit your needs is the PLC09 Modbus Arbitrator from Calta Computer Systems Limited.
http://www.calta.com/
This unit will allow up to three masters to poll a single Modbus slave.
Ian Milne
The Miille Applied Research Multii-Port is specifically designed for connecting multiple Modbus masters to a network one or more slaves. You can see a data sheet here:
http://www.miille.com/din366-10p.pdf.
Jerry Miille
http://www.miille.com/din366-10p.pdf.
Jerry Miille
Hello...
Check out ProSoft Technology's ProLinx line of products - they've been doing this for years.
Here's a snip directly for the product page:
"The ProLinx Modbus Serial Port Expander module allows you to attach up to three separate Modbus master devices to a single Modbus slave."
Specifically, see: http://www.psft.com/content/view/full/8891
CH
Check out ProSoft Technology's ProLinx line of products - they've been doing this for years.
Here's a snip directly for the product page:
"The ProLinx Modbus Serial Port Expander module allows you to attach up to three separate Modbus master devices to a single Modbus slave."
Specifically, see: http://www.psft.com/content/view/full/8891
CH
Thanks for the info. Are there any that can support up to 115.2k baud? (Not absolutely necessary, but good to know.) Thank you.
Your use of this site is subject to the terms and conditions set forth under Legal Notices and the Privacy Policy. Please read those terms and conditions carefully. Subject to the rights expressly reserved to others under Legal Notices, the content of this site and the compilation thereof is © 1999-2009 Nerds in Control, LLC. All rights reserved.
Our Advertisers
Help keep our servers running...
Patronize our advertisers!
Patronize our advertisers!




