3. Classification RS- 485 Communication FAQ No. 1-001-01 Author Hans Version 1.0.0 Date 2014/04/10 Page 3/3 ICP DAS Co., Ltd. Te chnical document Revision History Revision Date Description 1.0.0 2014/04/10 First released

2. Classification RS- 485 Communication FAQ No. 1-001-01 Author Hans Version 1.0.0 Date 2014/04/10 Page 2/3 1. Use ICP DAS converter: ICP DAS converter comes with pull high and pull low resistors. It can stable the communication signal on RS- 485 network. For more detailed information, please refer to http://www.icpdas.com/root/product/solutions/i ndustrial_communication/industrial_communic ation_products.html#Converter 2. Add pull high and pull low resistors: Users can add pull high and pull low resistors on RS-485 network for stable communication signal 3. Add tM-SG4: tM-SG4 comes with pull high and pull low resistors. It also can stable communication signal on RS-485 network. For more detailed information, please go to http://www.icpdas.com/root/product/soluti ons/signal_conditioning_modules/sg-700/tm- sg4.html ICP DAS Co., Ltd. Te chnical document

1. Classification RS- 485 Communication FAQ No. 1-001-01 Author Hans Version 1.0.0 Date 2014/04/10 Page 1/3 How to troubleshoot communication problems on RS-485 network? Problem phenomenon: 1. Communication failed with remo te I/O modules/units. 2. Using the other brand RS -485 converter (not ICP DAS converter). 3. Users’ tools or programs some times meet communication problem such as failed to read data or timeout error. ICP DAS Remote I/O modules/units need pull high and pull low resistors for stable signal on the RS-485 network. If the impendence does not match with requi rement, the signal on RS-485 may become unstable as below. It will cause communication problems. Below are some suggestions to solve the problem: ICP DAS Co., Ltd. Te chnical document Applies to: Platform Module Converter PC, NB, HMI,and other master devices I-7K,M-7K,,I-87K,87Pn and other RS-485 remote I/O modules/units Other brand converter (Not ICP DAS converter) ICPDAS Remote I/O Modules/Units list: htt p ://www.ic p das.com/root/ p roduct/solutions/remote io/remote io p roducts.html