WORKAROUND AVAILABLE: Modbus Master module on ION7xxx/8xxx devices disables communications for 30 minute periods in response to communications timeouts
Issue
Modbus Master module on ION7xxx/8xxx devices disables communications for 30 minute periods in response to communications timeouts
resolution
Certain customers may notice that ION7/8xxx meters where they are using Modbus Master modules stop communicating for period of 30 minutes at a time. This is due to hard-coded functionality in the meter firmware that automatically disables the Modbus Master module in the case that a certain timeout condition is reached.
In some cases, this automatic hard-coded functionality is not desirable. If that is the case, application engineers may work around this functionality by putting an ION framework in place that basically circumvents the default functionality incorporated into the firmware. For those unfamiliar with the terminology, an ION framework is application logic using linked ION modules configured in a specific way.
Please find attached two files - a PDF and an FWN file. The PDF file gives a basic description of the flow of the logic of the framework and how to develop it using the ION Designer component of Power Monitoring Expert (PME), StruxureWare Power Monitoring (SPM) or ION Enterprise (IONE) software. The FWN file may be used to paste the framework to a device using the Edit>"Paste from framework" functionality.
Note that one can modify the timing of the operation of this framework by editing the settings of the various modules. According to the firmware developer's reading of the code, the Modbus Master module is hard-coded to disable itself upon the expiry of 3 x 100second timeouts in row . This amounts to at least 300 seconds (i.e. 5 minutes). Based on this information, this framework should work as documented however one customer has reported that he had to make some slight changes to its operating parameters to make the framework completely effective in his particular operating environment. The following recommendation appeared to improve its performance in his particular context. Since this may apply to other customers as well, here is a suggestion for how to modify the framework to reduce the duration of the test period:
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Reduce the period of the One Shot timer module so that fewer packets are allowed to be sent out by the enabled Modbus Master module before it is disabled in the case that bad communications are detected. I would start by reducing this to say 16 seconds at first and then 15, 14 etc. This time window needs to be big enough to allow at least 3 packets to be sent out unless you reduce the threshold of the Setpoint modules from 3 to 2, for example.
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In the interest of learning more about the effectiveness of this workaround in the field, please feel free to report any successes or failures from the implementation of this framework to Darren Milligan using the following contact information: darren.milligan@schneider-electric.com , +1 250 652 7100 ext. 7519 .
Modbus Master module on ION7xxx/8xxx devices disables communications for 30 minute periods in response to communications timeouts
resolution
Certain customers may notice that ION7/8xxx meters where they are using Modbus Master modules stop communicating for period of 30 minutes at a time. This is due to hard-coded functionality in the meter firmware that automatically disables the Modbus Master module in the case that a certain timeout condition is reached.
In some cases, this automatic hard-coded functionality is not desirable. If that is the case, application engineers may work around this functionality by putting an ION framework in place that basically circumvents the default functionality incorporated into the firmware. For those unfamiliar with the terminology, an ION framework is application logic using linked ION modules configured in a specific way.
Please find attached two files - a PDF and an FWN file. The PDF file gives a basic description of the flow of the logic of the framework and how to develop it using the ION Designer component of Power Monitoring Expert (PME), StruxureWare Power Monitoring (SPM) or ION Enterprise (IONE) software. The FWN file may be used to paste the framework to a device using the Edit>"Paste from framework" functionality.
Note that one can modify the timing of the operation of this framework by editing the settings of the various modules. According to the firmware developer's reading of the code, the Modbus Master module is hard-coded to disable itself upon the expiry of 3 x 100second timeouts in row . This amounts to at least 300 seconds (i.e. 5 minutes). Based on this information, this framework should work as documented however one customer has reported that he had to make some slight changes to its operating parameters to make the framework completely effective in his particular operating environment. The following recommendation appeared to improve its performance in his particular context. Since this may apply to other customers as well, here is a suggestion for how to modify the framework to reduce the duration of the test period:
=================================
Reduce the period of the One Shot timer module so that fewer packets are allowed to be sent out by the enabled Modbus Master module before it is disabled in the case that bad communications are detected. I would start by reducing this to say 16 seconds at first and then 15, 14 etc. This time window needs to be big enough to allow at least 3 packets to be sent out unless you reduce the threshold of the Setpoint modules from 3 to 2, for example.
=================================
In the interest of learning more about the effectiveness of this workaround in the field, please feel free to report any successes or failures from the implementation of this framework to Darren Milligan using the following contact information: darren.milligan@schneider-electric.com , +1 250 652 7100 ext. 7519 .
Released for: Schneider Electric Egypt and North East Africa
