A
We are getting ready to modernize some of our older control systems with a more modern ethernet based (at least the HMI) control system. I want to add the capability for the operators/technicians to be able to wander around the entire plant with a mobile HMI and be able to be in touch with the control system using wireless ethernet. There are two parts to implement this - the wired access point and the mobile/client device
Access point - I have read plenty on various technologies. There are lots of different technologies available - as best I can tell, the industrial technologies generally use frequency hopping as the more reliable method of transmission, but at the penalty of bandwidth. I intend for the receiver/client device to be able to pull up the exact same graphics as a wired operator interface - reasonable bandwidth is of some concern. We are also outside with many cinder block and metal buildings, tanks, columns, structures, etc. The plant site is maybe 10 acres. Lots of vendors list ~30Km for line of sight distances with only several hundred feet for "inside" or I suppose not line of sight distances. Do I need lots of transmitters to effectively cover my area? What about the strength of the client's transmitter?
Obviously even if I have a strong transmitter for the access point, the client needs to be able to effectively transmit data back to the access point. I am not doing control with this wireless network - no PLC to PLC communication or anything like that - so it is not mission critical, but it is reasonably critical that the operator maintains communication with his process.
Along the lines of the mobile client, is there anything out there with reasonable resolution (at least 640 x 480). Anything rated for Cl I, Div II or Cl I, Div I? We would be using Windows Terminal Services at the server for the client to access the control system.
I would appreciate hearing about people's experience actually implementing a wireless network - especially outside with similar obstructions to ours.
Any information to help me figure out what to do would be helpful.
Thanks
Adam
Access point - I have read plenty on various technologies. There are lots of different technologies available - as best I can tell, the industrial technologies generally use frequency hopping as the more reliable method of transmission, but at the penalty of bandwidth. I intend for the receiver/client device to be able to pull up the exact same graphics as a wired operator interface - reasonable bandwidth is of some concern. We are also outside with many cinder block and metal buildings, tanks, columns, structures, etc. The plant site is maybe 10 acres. Lots of vendors list ~30Km for line of sight distances with only several hundred feet for "inside" or I suppose not line of sight distances. Do I need lots of transmitters to effectively cover my area? What about the strength of the client's transmitter?
Obviously even if I have a strong transmitter for the access point, the client needs to be able to effectively transmit data back to the access point. I am not doing control with this wireless network - no PLC to PLC communication or anything like that - so it is not mission critical, but it is reasonably critical that the operator maintains communication with his process.
Along the lines of the mobile client, is there anything out there with reasonable resolution (at least 640 x 480). Anything rated for Cl I, Div II or Cl I, Div I? We would be using Windows Terminal Services at the server for the client to access the control system.
I would appreciate hearing about people's experience actually implementing a wireless network - especially outside with similar obstructions to ours.
Any information to help me figure out what to do would be helpful.
Thanks
Adam