> For the complete documentation index, see [llms.txt](https://help.security.gallagher.com/knowledge-hub/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.security.gallagher.com/knowledge-hub/products/cc-software/configure/interface-options/api/ascii-interface-crps.md).

# ASCII interface

Compare ASCII interface options for Command Centre and third-party systems.

Many systems are capable of receiving ASCII text commands to trigger actions, or to notify them of external events. Common systems using this type of interface are matrix switches, fire panels, DVR systems, and paging systems.

**Part number:** `C12669`

## The three options

Gallagher provides three options for an ASCII text interface.

1. **Middleware plugin.** The plugin interface mechanism allows the Gallagher Controller to send out ASCII text strings to a third-party system in response to Gallagher events. A separate middleware PC is required to host the plugin.
2. **Controller-Resident RS232 ASCII Text Plugin.** Enables Command Centre to send and receive ASCII strings to and from a third-party system on another network, from the Gallagher Controller RS232 port.
3. **Controller-Resident TCP ASCII Text Plugin.** The same, from the Gallagher Controller TCP port.

Options 2 and 3 are hosted on the Gallagher Controller 6000, deploying the Controller Resident Plugin Support customization, so no separate middleware PC is required.

> ⚠️ The controller-resident plugins can manage a connection to another device, and can both send and receive ASCII data on that connection. They **cannot accept an incoming TCP connection initiated by another device**, and the connection must be persistent.

## Choosing between them

The older ASCII Text plugin needs Middleware plus the ASCII Text Plugin, often over RS232 through a **MOXA** converter. The Controller-Resident Plugin removes the Middleware entirely, and usually the MOXA with it: a Controller 6000 sends ASCII straight out its TCP or RS232 port.

**Versions supported:** Command Centre **v8.20 through v9.40** (Controller Resident Plugin Support customization). The Controller-Resident Plugin is available from **v7.20** onwards.

> 🧭 **Where to start**
>
> * **Setting up incoming or outgoing strings?** → [Controller Resident Plugin (CRPS)](/knowledge-hub/products/cc-software/configure/interface-options/api/crps-basic-configuration.md)
> * **Need the wider middleware picture?** → [Controller API (FTCAPI) and Middleware Framework (FMF)](/knowledge-hub/products/cc-software/configure/interface-options/api/controller-api-ftcapi-and-middleware-f.md)

**Documentation:** Release Note Controller Resident Plugin Support, published for each version from v8.20 through v9.40.


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