> 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/mbstp-register.md).

# MBSTP 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 MBSTP register contains the Modbus Stop Bits configuration. The default value is 131, representing One Stop Bit, which is the default Modbus Stop Bit.

Allowed configuration values range from 131 to 132; attempting to write any other values will not have any effect.

* Value 131 (default) One Stop bit (default).
* Value 132 Two Stop bit.

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:** MBSTP
* **Description:** Stop Bits Configuration
* **Register Address:** 503 (0x1F7)
* **Default value:** 131 (0x0083)
* **Memory Type:** Non-Volatile RAM
* **Allowed values:** 131 and 132 (0x0083 and 0x0084)

| Bit 15 to Bit 8 | Bit 7 to Bit 0  |
| --------------- | --------------- |
| -               | MBSTP \[7 to 0] |