ICP DAS releases two new redundant communication mechanisms for ISaGRAF PAC (Programmable Automation Controller) monitor/control system to implement RS-485 or Ethernet network communication redundancy. It increases the system efficiency, no more communication interruption, never fail the data transmission!

In most of the distributed control systems, there is only one communication network within the central control station and the local control stations. If the communication wire damaged or disconnected, that local station will lost contact and the central station will not control the local devices anymore until repairing the communication wiring. Many applications cannot allow any communication breakdown that will occur to lot of cost and risks. The more the repair time is, the more the losses and risks will be. Therefore, we apply the following two redundant communication mechanisms to solve the problem.

In this mechanism, the PAC in the central station is Modbus RTU Master, the PAC in the local stations are Modbus RTU Slaves. There are two sets of RS-485 connections in the central station to connect to two RS-485 serial ports of multiple local stations. When one connection fails, the system can detect out the local communication problems and immediately inform the engineers in time to repair. At the same time, the other connection is still in normal communication state to ensure the entire control system working well.

For long distance communication, please optional select I-2541 converter to convert RS-485 signals to fiber signals that can transmit a signal up to 2 km.
Please refer to website : http://www.icpdas.com/products/Industrial/communication_module/i-2541.htm

If the environment is not easy for wiring, please optional select ZB-2550P/ZB-2551P converter to convert RS-485 signals to wireless radio signals. (Wireless radio may be affected by some cover objects, the weather and wireless interference.)
Please refer to website : http://www.icpdas.com/faq/isagraf.htm > FAQ-110
http://www.icpdas.com/products/GSM_GPRS/zigbee/zb-2550p.htm
http://www.icpdas.com/products/GSM_GPRS/zigbee/zb-2551p.htm

In this mechanism, the PAC in the central station is Modbus TCP Master, the PAC in the local stations are Modbus TCP Slave. There are two sets of Ethernet connections in the central station to connect to two Ethernet ports of multiple local stations. When one connection fails, the system can detect out the local communication problems and immediately inform the engineers in time to repair. At the same time, the other connection is still in normal communication state to ensure the entire control system working well.

For long distance communication, please optional select the following converters to convert Ethernet signals to fiber signals.
NS-205FC , NS-205FT, NS-206FC, NS-206FT, NS-209FC, NS-209FT: max. 2 km or
NS-205FCS , NS-206FCS, NS-209FCS : max.15 km
Please refer to website : http://www.icpdas.com/products/Switch/switch_list.htm

The PAC (Programmable Automation Controllers) in the central control station and the district local stations of these two mechanisms are WinPAC-8xx7 (The abbreviation of WP-8147, WP-8447, WP-8847, WP-8137, WP-8437 and WP-8837.) User can also use VP-25W7, VP-23W7, XP-8047-CE6, XP-8347-CE6, or XP-8747-CE6 PAC. For more information about the relation
PAC products please refer to the following websites.
ISaGRAF PAC Data Sheet website : http://www.icpdas.com/products/PAC/i-8000/data%20sheet/data%20sheet.htm
ISaGRAF PAC website : http://www.icpdas.com/products/PAC/i-8000/isagraf.htm

For detail information and more configuration please refer to http://www.icpdas.com/faq/isagraf.htm > FAQ-119