Machine remote diagnosis allows initiation of the best course of action for problem resolution. When tracking problems or strange behaviour on a PLC controlled machine, it is often difficult or even impossible to correct the problem if it cannot be reproduced by the service staff. In the worst case scenario, the machine needs to be serviced on site to identify the problem, involving a local technician with all the communication, language and accent problems that may arise with the machine builder. Sounds familiar? The eWON industrial router provides the ability to pinpoint automation devices quickly without interfering with them. The eWON industrial router manages the complete alarm cycle. Several alarm thresholds are available on each eWON data tag, with individual settings for dead band and activation delays. In addition, real-time logging allows service staff to be better prepared for interventions with accurate diagnostic and first-hand information. Using either Point-to-Point (PPP) dial-up modem or internet connection, the eWON industrial router is your fast access to expertise.

Basic idea

Establishing an objective remote diagnosis first requires local data acquisition on serial and/or Ethernet based automation devices such as PLCs. In the automation world, local data acquisition must be processed with a dedicated serial or Ethernet protocol such as:   

• Modbus TCP, Modbus RTU;
• XIP, Uni-Telway;
• EtherNet/IP, DF1;
• FINS TCP, FINS  Hostlink;
• ISO TCP, PPI, MPI, Profibus;
• and ASCII

To fetch the PLC data - i.e. Register, Input/Output values, counter, data block, etc.-, eWON can be configured for this without the need to stop the PLC (no functional block to add in the PLC). By polling these data in the PLCs at defined intervals, eWON feeds its internal memory tags with live data. Up to 350 internal tag values can be stored in the eWON memory.

For each tag, the user can set-up Historical or Real-time data logging. Historical logging is a classic file that records a value either every second or only when a dead band value is exceeded. Each value is date and time stamped. In contrast, Real-time logging is a circular FIFO (First In First Out) buffer of defined values for a set sampling period.

Alarm notifications

Automated alarms and collection of information about device usage and health give machine builders the basis to improve the evaluation of a problem. To be notified of a problem, the user can define a triggering condition for each tag. Therefore, he does not need to be permanently connected to the machine to track the problem.

eWON industrial router embeds a complete alarm cycle mechanism with 4 phases. Each tag can have up to 4 thresholds, with a specific defined dead band value that can be set up in order to avoid hysteresis effects or unwanted alarms. Alarm notifications can be generated for each phase via email, SMS, and FTP put.

Once the alarm has been triggered, the machine builder receives a notification, most likely an email. Data logging files can be attached to the email notification, which allows the user to trace and diagnose the alarm events. eWON is also able to notify the alarm on its own via an outgoing PPP connection through its built-in modem and send the notification to the recipient. The attachment can be text files, formatted in “comma separated value” mode or binary files. The alarm notification could alternatively be sent as an SMS. This, of course, means that no attachment is possible in the SMS message but the attachment could be stored in parallel on an FTP server. For SMS, there is no need to have a GSM modem. In fact, even in the case where eWON embeds a PSTN modem, SMS notifications can be sent, if available, via the telecom operator SMS server.

Once notified by the SMS, a remote connection can be established by the service staff using either an incoming dial-up PPP connection to eWON or an Internet IP connection.

Advantages

eWON industrial router basic diagnosis features allow:

• Sending alarms in case of faults, performance losses or malfunctions with detailed information inside the alarm message.
• Local data logging, for diagnostic purposes or to offer HMI remote access for the improvement of the diagnostics.

Thanks to these functions, the eWON industrial router is able to send activity reports on what really happened on the machine so that live information can be obtained without remaining in communication with the machine or/and without requesting on-site help. The eWON industrial router does not interfere with the automation device and does not require the PLC to be stopped, which is a key competitive advantage compared to other teleservice solutions. Alarm and data logging configuration set up is made through eWON web pages giving the necessary flexibility to achieve any remote diagnostic operation required. Automated alert notifications and error reporting give the basis for improving uptime and planning in a cost-effective way. But it can also help to track very difficult reproducible problems.

Featured products

Remote diagnostics features are available in the eWON 4xxxCD industrial routers which offer the following modem options:

• Mobile/cellular (VPN): eWON ref. EW532x8 for GPRS quad band, eWON ref. EW532xB for UMTS (with fallback to EDGE/GPRS), eWON ref. EW532xA for HSUPA (with fallback to HSDPA, UMTS, EDGE or GPRS)
• ADSL (VPN): eWON ref. EW472x1 for ADSL, eWON ref. EW472x4 for ADSL with PSTN backup mode, eWON ref. EW472x7 for ADSL with GPRS/EDGE backup mode
  
• LAN connection (VPN): eWON ref. EW462x1

The ‘x’ in the reference number stands for:                

• ‘6’ if the MPI/Profibus protocol must be used for connection to the PLC(s)
• ‘0’ otherwise.