HIMax Safety Manual - Tuv-fs.com

11 Configuring Communication HIMaxNOTICEReceiveTMO also applies in the other direction from PES 2 to PES 1!Since ReceiveTMO is a safety-relevant component of the worst case reaction time TR (see11.2.1), its value must be calculated and manually entered in the safeethernet Editor.ReceiveTMO = 4*Delay + 5*maxZZWhere:DelaymaxZZDelay on the transmission path, e.g., due to specific hardwareMaximum cycle time of both controllers.If a correct response is not received from the communication partner within the"ReceiveTMO", safety-related communication is terminated and any variables importedthrough the communication channel are reset to their user-defined initial values.In networks where packets can be lost, the following condition must be given:ReceiveTMO ≥ 2 * Response Time (minimum)(valid for "Fast & Noisy" profile)If this condition is met, the loss of at least one data packet can be intercepted withoutinterrupting the safeethernet connection.If this condition is not met, the availability of a safeethernet connection can only be ensuredin a collision and fault-free network. However, this is not a safety problem for the processormodule!NOTICEThe maximum value permitted for ReceiveTMO depends on the application processand is configured in the safeethernet Editor, along with the expected maximumresponse time and the profile.NOTICEIn the following examples, the formulas for calculating the worst case reaction timeonly apply for a connection with HIMatrix controllers if the parametersafety time = 2 * watchdog timehas been set in the systems.11.2.1 Calculating the Worst Case Reaction TimeThe worst case reaction time TR is the time between a change on the sensor input signal(in) of PES 1 and a reaction in the corresponding output (out) of PES 2. It is calculated asfollows:Page 60 of 70HI 801 003 D Rev.2.0