Brand: testo
Category: Data Logger
Document Type: Manual
Language: EN
Manual for Saveris 2
Uploaded: April 20, 2026, 7:58 p.m.
The testo Saveris 2 WiFi data logger system monitors temperature and humidity in storerooms and work rooms. It consists of WiFi data loggers and a Cloud data storage system. Loggers record readings and transmit them to the Testo Cloud via WLAN. Readings can be analyzed anytime, anywhere on a smartphone, tablet, or PC. Limit value violations are reported via e-mail or SMS. Loggers can also be programmed via the Testo Cloud.
First steps involve unpacking, removing the logger from the wall bracket, loosening the battery cover, removing insulation strips, and tightening the screws. A Quick Start Guide is available for assistance.
Offline configuration can be done using a PDF form (WifiConf.pdf) requiring Adobe Reader. Connect the logger to a PC, open the PDF, copy the Account ID, enter network name (SSID) and WLAN password, save the configuration, and then disconnect the USB.
Licences provide access to measuring functions. A free basic licence is included, with expansions available for purchase. The testo Saveris 2 App offers commissioning, network analysis, and push message functions. It requires installation on Android or iOS devices. For commissioning, a 5-minute hotspot mode on the loggers is needed.
Technical data includes sensor types, measuring ranges, accuracy, resolution, operating temperatures, storage temperatures, protection classes, measuring and communication cycles, memory, battery life, voltage supply, dimensions, and certifications.
User management allows for settings, account information, password changes, and logoff.
The command bar provides access to the Quick Start Guide, Online Help, and system messages.
System and status information includes alarm status display.
Frequently Asked Questions cover USB cable usage, WPA2 Enterprise encryption, configuration file issues, wireless connection interruptions, and error code explanations.
The Change History section details software updates and improvements made to the testo Saveris 2 Cloud.
Troubleshooting and error codes
| Error Code | Possible Cause | Solution |
|---|---|---|
| E03, E04, E05, E09 | An error has occurred in the WiFi data logger. | The error will automatically be corrected by the firmware. No action is needed. |
| E12 | The configuration file WifiConfig.xml indicates an error. | Use the Quick Start Guide to create a new configuration file and save it to the logger. |
| E20 | WPA2 Enterprise EAP connection needs to be configured, but no CA certificate was found. | Save the CA certificate in PEM format as "ca.pem" with the XML file or upload it in the web config. |
| E21 | Incorrect format of the ca.pem certificate. | Check if the certificate is in PEM or BASE64 format. Ensure it's not a bundle. Export or convert if necessary. |
| E22 | WPA2 Enterprise EAP-TLS connection needs to be configured, but no user certificate was found. | Save the user certificate in PEM format as "client.pem" with the XML file or upload it in the web config. |
| E23 | Incorrect format of the client.pem user certificate. | Check if the certificate is in PEM or BASE64 format. Ensure it's not a bundle. Export or convert if necessary. |
| E24 (Older generation logger, prior to 2016) | Low battery. | Insert new batteries. If the problem persists, reset the logger to factory settings (hold control key for > 20 s). |
| E25 | Incorrect format of the private.key certificate. | Check if the certificate is in PEM or BASE64 format. Ensure it's not a bundle. Export or convert if necessary. |
| E26 | Possible reasons: Access point out of range/off; Incorrect network name (SSID); Unsupported encryption method. | 1. Check access point availability and logger location. 2. Verify network name and create a new config file if needed. 3. Configure the access point with a supported encryption method (WEP, WPA (TKIP), WPA2 (AES, CCMP)). |
| E32 | WiFi data logger has not obtained an IP address. | 1. Check network password. 2. Check access point MAC filter settings. |
| E35 | No reply to test ping from access point. | Ensure ping to the gateway is allowed within the access point configuration. |
| E36 | DNS could not be resolved. | 1. Check the access point's internet connection. 2. Check if routing within the network infrastructure is working. |
| E41 | Cannot obtain current time from a time server. | 1. Check the access point's internet connection. 2. Ensure the NTP port (123/UDP) is open. |
| E51 | Could not connect to the Testo Cloud. | 1. Testo Cloud servers may be temporarily inaccessible. 2. Check if TCP ports (1883 or 8883) of the access point are open in both directions. |
| E52 | Data logger is already logged into another account. | Log the data logger out of the existing account first. |
| E63 | Could not send data to the Testo Cloud. | 1. Check internet connection stability. Data will transfer in the next cycle, or initiate manually. 2. Testo Cloud server may be temporarily inaccessible. |
| E75 | Firmware update failed. | Check internet connection stability. Data will transfer in the next cycle. |
| Warning: Err AccountID | AccountID in configuration file is invalid. | Use the Quick Start Guide to create a new configuration file. |
| Warning: no AccountID | No AccountID in the configuration file. | Use the Quick Start Guide to create a new configuration file. |
| Warning: no License | Number of connected loggers exceeded or license expired. | Log off another logger, extend or renew the license. |
| Warning: not Active | WiFi data logger has been deactivated. | Activate the WiFi data logger under Configuration --> WiFi data logger. |