Yang, M. Kamikubota, N. Kikuzawa, N. Sato, K.C. Tajima, Y. JACoW Publishing Geneva, Switzerland 2226-0358 978-3-95450-221-9 10.18429/JACoW-ICALEPCS2021-THPV029 English 927-930 timing operation LLRF proton controls Contribution to a conference proceedings 2022 2022-03 https://doi.org/10.18429/JACoW-ICALEPCS2021-THPV029 https://jacow.org/icalepcs2021/papers/thpv029.pdf Since 2006, the Japan Proton Accelerator Research Complex (J-PARC) timing system has been operated successfully. However, there were some unexpected trig-ger-failure events, typically missing trigger events, during the operation over 15 years. When a trigger-failure event occurred, it was often tough to find the one with the fault among many suspected modules. To solve the problem more easily, a unique device, triggered scaler, was devel-oped for reading back accelerator signals. The performance of the module has been evaluated in 2018. In 2021, we measured and observed an LLRF sig-nal as the first signal of the read-back system for beam operation. After firmware upgrades of the module, some customized timing read-back systems were developed, and successfully demonstrated as coping strategies for past trigger-failure events. In addition, a future plan to apply the read-back system to other facilities is discussed. More details are given in the paper.