> For the complete documentation index, see [llms.txt](https://docs.monokot.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.monokot.io/tags-and-devices/iec-60870-5-104-connectivity/parameters.md).

# Parameters

Listed below are common parameters for primary device and subdevice.

### General <a href="#h.v0x6m2bzuwsv" id="h.v0x6m2bzuwsv"></a>

* **Common Address:** specifies common address of the controlled station.
* **Device Time Zone:** specifies time zone of the controlled station. This parameter is used to convert the timestamp during time synchronization and processing control and monitoring ASDUs. The default setting is \[Local Time Zone], which corresponds to the local time zone of the system the server is deployed on.
* **Enable Reads:** specifies that the driver should send a command to read C\_RC\_NA\_1 data for all associated monitor tags with the frequency specified in the *Update Rate* parameter of each tag.

### Services <a href="#h.r5fyatnqzslj" id="h.r5fyatnqzslj"></a>

* **General Interrogation (Initialization Settings):** specifies whether the driver should send a general interrogation command (C\_IC\_NA\_1) after connecting or reconnecting. The default value is *Connect/Reconnect.*
* **General Interrogation Mode (Periodic Settings):** specifies whether the driver should periodically send a general interrogation command (C\_IC\_NA\_1). The default value is *Disabled.*
* **General Interrogation Interval (Periodic Settings):** defines the time interval (in seconds) for periodic sending of the general interrogation command (C\_IC\_NA\_1). The default value is *3600.*

{% hint style="info" %}
Please note that general interrogation command is generated with the qualifier of QOI = 20 (station interrogation)
{% endhint %}

* **Counter Interrogation (Initialization Settings):** specifies whether the driver should send a counter interrogation command (C\_CI\_NA\_1) after connecting or reconnecting. The default value is *Disabled.*
* **Counter Interrogation Mode (Periodic Settings):** specifies whether the driver should periodically send a counter interrogation command (C\_CI\_NA\_1). The default value is *Disabled.*
* **Counter Interrogation Interval (Periodic Settings):** defines the time interval (in seconds) for periodic sending of the counter interrogation command (C\_CI\_NA\_1). The default value is *3600.*

{% hint style="info" %}
Please note that counter interrogation command is generated with the qualifier of QCC = 5 (request general counter group)
{% endhint %}

* **Time Sync (Initialization Settings):** specifies whether the driver should send a time synchronization command (C\_CS\_NA\_1) after connecting or reconnecting. The default value is *Connect/Reconnect.*
* **Time Sync Mode (Periodic Settings):** specifies whether the driver should periodically send a time synchronization command (C\_CS\_NA\_1). The default value is *Periodically.*
* **Time Sync Interval (Periodic Settings):** defines the time interval (in seconds) for sending the periodic time synchronization command (C\_CS\_NA\_1). The default value is *3600.*
* **Test Mode (Periodic Settings):** specifies whether the driver should periodically send a testing command (C\_TS\_NA\_1). The default value is *Disabled.*
* **Test Interval (Periodic Settings):** defines the time interval (in seconds) for sending the periodic testing command (C\_TS\_NA\_1). The default value is *15.*

Listed below are the common parameters of primary device that are used to organize the data transmission channel.

### Advanced <a href="#h.y013kqh7x99t" id="h.y013kqh7x99t"></a>

* **Originator Address:** specifies the client’s originator address. Takes a value from 0 to 254.
* **Max ASDU Size:** specifies the maximum size of the generated ASDU (in bytes).
* **Size of IOA:** specifies the size of the the information object address (1, 2 or 3 octets). Note that all tags associated with the device whose information object address does not fit in the specified number of octets will be ignored by the driver.
* **Size of COT:** specifies the cause of transmission field size (1 or 2 octets).
* **Size of CA:** specifies the size of the common address field (1 or 2 octets). Note that the parameter cannot be changed if the *Common Address* of the device or any of the subdevices does not fit in the specified number of octets.
* **Max Buffer Size:** specifies the maximum number of ASDUs that the scan buffer can contain.

### SSL <a href="#h.vlixmhi3jfb7" id="h.vlixmhi3jfb7"></a>

* **Use SSL:** specifies whether the driver should establish a secure connection with the controlled station.
* **Client Certificate:** specifies a client-side security certificate. Note that the certificate must contain both public and private encryption keys.
* **SSL Verification**:  contains verification mode of controlled station SSL certificate:
  * Accept any.
  * Verify chain of trust by using a store of certificates of the operating system
  * Verify chain of trust by using custom certificate of certification authority
* **Custom CA File:** contains custom certificate of certification authority