> For the complete documentation index, see [llms.txt](https://inacks.gitbook.io/is4310-wiki/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://inacks.gitbook.io/is4310-wiki/datasheet/memory-description/mbpar-register.md).

# MBPAR Register

> This page is not the authoritative source for design information. The official [IS4310 datasheet](https://www.inacks.com/is4310) published on [www.inacks.com](http://www.inacks.com) is the authoritative reference: always consult it for the latest information.

The MBPAR register stores the Modbus Parity Bit configuration. The default value is 122, representing Even Parity, which is the default Modbus Parity.

Allowed configuration values range from 120 to 122; attempting to write any other values will not have any effect.

* Value 120 represents No Parity.
* Value 121 represents Odd Parity.
* Value 122 (default) represents Even Parity.

This register is placed at the end of the Holding Register section to minimize the risk of accidentally overwriting the Modbus configuration registers. 

Any modifications to this register will be saved in the internal non-volatile memory, which supports up to 10,000 cycles. A write cycle occurs only if the written data differs from the previous value. The write process takes 25ms. Upon power-up, the IS4310 automatically retrieves the last saved configuration.

* **Name:** MBPAR
* **Description:** Parity Bit Configuration
* **Register Address:** 502 (0x1F6)
* **Default value:** 122 (0x007A)
* **Memory Type:** Non-Volatile RAM
* **Allowed values:** 120 to 122 (0x0078 to 0x007A)

<table><thead><tr><th width="200">Bit 15 to Bit 8</th><th width="100">Bit 7</th><th>Bit 6 to Bit 0</th></tr></thead><tbody><tr><td>-</td><td>-</td><td>MBPAR [6 to 0]</td></tr></tbody></table>