# IOMod Modbus RTU Slave firmware change-log

Elseta IOMod series devices support's **Modbus RTU** Slave protocol.

<p class="callout info">This firmware can be used for IOMod series devices: IOMod 8DI8DO v1.x, IOMod 16DI v1.x, IOMod 8AI v1.x, IOMod 4RTD v1.x, IOMod HT v1.x</p>

<p class="callout warning">This version does not support IOMod 4Cs4Vs model. </p>

<table border="1" id="bkmrk-firmware-version-rel" style="border-collapse: collapse; width: 100%; height: 155px;"><tbody><tr style="height: 29px;"><td style="width: 25.7091%; height: 29px;">Firmware</td><td style="width: 8.1599%; height: 29px;">Version</td><td style="width: 14.3387%; height: 29px;">Release Date</td><td style="width: 51.9159%; height: 29px;">Changes</td></tr><tr><td class="confluenceTd" style="width: 25.7091%;">IOMOD\_MODBUS\_v1\_21\_0.bin</td><td class="confluenceTd" style="width: 8.1599%;">1.21</td><td class="confluenceTd" style="width: 14.3387%;">2023-07-26</td><td class="confluenceTd" style="width: 51.9159%;">- added 8DI4RO support

</td></tr><tr style="height: 68px;"><td style="width: 25.7091%; height: 68px;">IOMOD\_MODBUS \_v1\_19.bin</td><td style="width: 8.1599%; height: 68px;">v1.19</td><td style="width: 14.3387%; height: 68px;">2020-07-01</td><td style="width: 51.9159%; height: 68px;">- Fixed SPI readings for IOMod 8AI by lowering SPI clock speed to 400kHz

</td></tr><tr style="height: 29px;"><td style="width: 25.7091%; height: 29px;">IOMOD\_MODBUS \_v1\_18.bin</td><td style="width: 8.1599%; height: 29px;">v1.18</td><td style="width: 14.3387%; height: 29px;">2019-08-23</td><td style="width: 51.9159%; height: 29px;">- Fixed crash introduced by a higher range of temperatures (&gt;40 C)

</td></tr><tr style="height: 29px;"><td style="width: 25.7091%; height: 29px;">IOMOD\_MODBUS \_v1\_17.bin</td><td style="width: 8.1599%; height: 29px;">v1.7.3</td><td style="width: 14.3387%; height: 29px;">2019-01-30</td><td style="width: 51.9159%; height: 29px;">- Fixed possible race condition where two or more inputs change at once and stop IOMod device from calculating input calculations further. Inputs are now polled every 1 ms.

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