Here is an update on the latest version changes:
V5.2 B7 (29-1-2026)
– Users & rights -> Operators may change their own passwords.
– Parameter settings -> Possibility to specify a factor & offset with 9 digit resolution.
– Critical issue addressed -> 525 data logger could stall when performing a remote firmware upgrade.
V5.2 B5 (9-1-2026)
– ML-525 configuration upload -> Added support for loading ML-x17 configuration files converted with ydocTerminal v3.32 into ML-525 format.
– SDI-12 sensor driver ->Fixed an issue where excessive inter-character spacing caused some sensors to become non-responsive.
– ML-OI-AD-10V option board -> Port mode re-enabled for the 0-1.25 V, 0-2.5 V and 0-5 V ranges.
V5.2 B4 (11-12-2025)
– SD storage -> Implemented a log data ring buffer, older entries are overwritten when full. 112 MB on the internal 525 flash and up to 4 GB on the external SD card.
– SD storage -> Data storage efficiency enhanced to support 10Hz data logging on multiple parameters.
– MQTT Sparkplug B -> Added QoS selection for NDATA messages.
V5.2 B2 (18-11-2025)
– Digital pulse driver -> Added a small initialization delay when using Internal Pull-Up with Rising Edge to prevent false counts.
– MODBUS driver -> Added a short post-receive delay before transmitting the next command to improve frame detection by the MODBUS device and reduce occasional retries.
– Calculations driver -> Added day-of-week variable wday (0–6, Su–Sa) to enable week-based decisions.
V5.2 B1 (8-10-2025)
– ML-525SE -> Initial firmware release of the ML-525SE
V5.1 B6 (7-10-2025)
– Camera driver -> Automatic IR night-vision calibration ensures true grayscale images — no more purple night shots.
V5.1 B5 (11-8-2025)
– Modem driver -> RTS pulse width increased to reliably wake modem from deep power-saving sleep .
– FTP driver -> Work around to handle truncated modem CONNECT messages after FTP STOR command (causing empty or faulty files to appear sometimes).
– Administrator and user password -> Made more secure according to EU RED recommendations.
– Configuration snippets upload -> Removed too strict checking of interval configuration rules (be careful of anomalies).
– Modem power on pulse enlarged as it was to short for the ME910C1-WW Modem (affected firmware versions 5.0 and 5.1).
V5.1 B1 (5-6-2025)
– Modem driver -> Temperature control added to prevent overheating damage.
– Parameter settings menu -> Feature added to skip or clip sample values when outside defined boundaries.
– Calculated channels driver -> The initial value of a parameter can now be accessed using the .IV attribute, allowing you to use it as a literal/reference value in your calculations.
– ASCII output driver -> The update interval can now be set to any value (e.g., to match a faster sample rate instead of the data log interval).
– Auxiliary output boards (ML-OO) -> The update interval can now be set to any value (e.g., to match a faster sample rate instead of the data log interval).
V5.0 B5 (8-5-2025)
– Maintenance menu -> Improved YDOC-format data download performance.
– Alarm settings menu -> Added option to exclude drivers with an independent interval from instantaneous taken measurements upon alarm raise or fall.
– MODBUS sensor driver -> Added choice of write function: multiple-register (0x10) or single-register (0x06), for “start maintenance” and “start measurement” commands.
V5.0 B4 (1-4-2025)
– Critical bug fix -> Too long data records could stall communication. Affected version V5.0B3 only.
V5.0 B3 (28-3-2025)
– Bug fix data output -> Long data records were occasionally truncated when containing more than approximately 40 parameters .
V5.0 B1 (18-3-2025)
– Modem settings -> Threshold standby time feature added. To save power, the data logger turns off the modem after data transfers. However, since network registration consumes power and time, keeping the modem on can be beneficial if the next session occurs soon. This setting allows you to specify how long the modem stays powered for reuse within the set time.
– Serial sensor drivers -> Independent log interval option added for serial devices.
– Digital pulse driver -> Parameter added for instant pulse event logging.
– Serial sensor drivers -> Independent log interval option added for serial devices.
– Camera driver -> Skipping interval shift when alarm interval is active.
V4.9 B4 (13-1-2025)
– Bug fix TCP terminal tunnel -> After a remote session the TCP terminal stayed active and did not shutdown the modem causing data transfer to stall. Affected versions are 4.9B2 and 4.9B3 only.
Important notice: Do not upgrade the affected versions through a remote hands-on TCP terminal interface. Perform the upgrade locally or via ydocTerminal->Tools->Remote Firmware Upgrade.
V4.9 B3 (6-12-2024)
– Bug fix power monitor -> The low-power check has been improved to prevent occasional incorrect temporary disabling of the modem
– Swarm satellite driver -> Removed as it became obsolete after the last satellites were deorbited.
– Bug fix power monitor -> The power too low checking improved for Lithium power boards and loggers using digital inputs only.
V4.9 B1 (14-11-2024)
– Wifi output -> Email stack added
– Email driver -> New SMTP stack with implicit TLS support
– Calculated channels driver -> Functions day of year and bt (between) added
– Calculated channels driver -> Empirical formulas added for wind chill, dewpoint and ntc thermistor
– Parameter settings -> Alarm reset delay added
– Warm up times for sensor and accessory power enlarged to max 15 minutes
– Bug fix option boards detection -> Retry mechanism implemented to prevent occasional option board not detected
V4.8 B17 (14-5-2024)
– Modem driver -> Warm up time enlarged for ME910G1 Modem (ML-417) to avoid “SIM busy” messages.
– Bug fix digital drivers -> A depleted clock battery caused regular counter resets.
V4.8 B16 (29-4-2024)
– Modem driver -> Suspending modem operations in case of low battery to avoid modem damage.
– Radio driver -> Custom NMEA-0183 output format added.
– Bug fix JSON output -> Auto converting double quotes in texts to single to avoid JSON validation errors.
– Bug fix digital pulse driver -> Max rate and Min rate only calculated over completed scheduled intervals.
– Configuration upload -> Configuration snippets extended to (p)reset digital input counters.
– Configuration upload -> Configuration snippets extended to change alarm SMS phone numbers.
V4.8 B15 (2-4-2024)
– Bug fix WiFi data sending stalls (affected versions 4.8B11 – 4.8B14).
– Bug fix FTP driver -> Sending camera pictures was disabled when FTP output type was set to sending heartbeats only.
V4.8 B14 (6-2-2024)
– BLE-driver -> Important bug fix! Starting from FW 4.6B1, it has become apparent that the ML-OU-BLE board is responsible for a high quiescent current, potentially resulting in the premature depletion of batteries.
V4.8 B13 (17-1-2024)
– MQTT driver -> Sparkplug-B protocol adapted to report data quality (GOOD, BAD and STALLED).
– Bug fix data alarms driver -> Suppressing the unnecessary second measurement run directly after a data alarm occurrence.
– Bug fix digital pulse driver -> Preventing data logger to wait until next scheduled datalog interval when a unscheduled datalog was activated by alarm occurrence.
V4.8 B10 (8-11-2023)
– HTTP driver -> The Extended path edit field now supports substitution tokens for amongst others device serial number and name.
– Analog sensors -> One of the analog inputs can be used for digital and/or dead-band triggered 100Hz burst recording to capture up to 5 seconds of a signal transition in detail.
V4.8 B8 (28-9-2023)
– Auxiliary input option board drivers -> 100ms wake-up delay added before addressing ML-OI-AX option boards to prevent board detection errors.
– Network signal sensor driver -> Selection of sample log interval less than data log interval or 1 minute inhibited.
V4.8 B7 (31-8-2023)
– Bug fix digital pulse driver -> The Mean Rate is restored to previous implementation which was correct for aggregation use (see V4.8B5).
– Modem driver -> Automatic Network deregister and register mechanism implemented to cope with sudden network subscribing issues.
– FTP driver -> Automatic switching from active to passive FTP mode only done after 5 consecutive errors to rule out incidental Network drops.
– MODBUS sensor driver -> Timeout enlarged from 1.5 to 3 seconds.
V4.8 B6 (1-8-2023)
– Bug fix FTP -> The ME910C1-WW Modem gives “#FTPSIZE: 0” instead of “File not found” error messages and causes the state machine to go to the wrong state.
– Bug fix aggregations driver -> Suppressing error log message “Aggregations;Has invalid data” when aggregations are not even used.
V4.8 B5 (25-7-2023)
– Modem driver -> Network registration timeout enlarged from 2 to 3 minutes to cope with roaming delays.
– Modem driver -> For CHAP authentication on 4G modems we have replaced the obsolete AT#GAUTH command with the preferred AT+CGAUTH or AT#PDPAUTH commands.
– Bug fix digital pulse driver -> When the sample rate is not equal to the data log interval the Mean Rate was calculated wrongly.
– Created ‘S’ystem log messages for drivers with invalid data (*I) like: “S;230703154200;INV;HART inputs;Has invalid data”.
V4.8 B3 (28-6-2023)
– HTTP driver -> Security options “Token” and “Custom Header” authorization implemented
– Activation of the sensor power adjusted with two start pulses to prevent the sensor power being switched off due to sensors with a high capacitance.
– Digital alarm input driver -> Trigger delay option time enlarged to maximum 1 hour.
– Bug fix digital pulse driver -> When an Alarm is set on a sample rate in between the data log interval, Max/Min and Mean Rate were cleared wrongly.
– Bug fix virtual serial port tunnel driver -> Warm up time not taken into consideration for the normal pre wake up time.
– Bug fix digital alarm input driver -> Alarm state did not reflect proper text (Showing “Not recent” or “Invalid”) when never activated.
V4.8 B1 (30-5-2023)
– Digital Alarm output driver -> Parameters added to count alarm activations and durations
– Digital Alarm output driver -> Mode added to make or break the output on alarm
– Bug fix MQTT driver -> Long diagnostic messages could cause erratic behavior during SparkplugB sessions.
V4.7 B6 (8-5-2023)
– Modem output -> Modem output suspended when the LFP battery is too low (< 3.1 Volts) to allow the LFP battery to charge and prevent damage to the modem
– Bug fix aggregated channels driver -> Rare rate of change parameter spike anomaly fixed
– Bug fix CSV output format -> Event/System messages formatted as quoted text to prevent a field separator in the text from adding additional columns
– Bug fix DAS output format -> Converting the occasionally occurring comma to decimal point in event/system messages as the comma is a field separator
V4.7 B4 (22-3-2023)
– Information (“I”) record added for YDOC data format with Logger identification, IMEI and SIM ID’s
– FTP driver -> Code for uploading files changed, because some FTP servers don’t allow wild-cards (*) anymore
– Bug fix FTP driver -> Automatic uploading files didn’t work when also sending camera jpeg files
– Bug fix FTP driver -> LE910C1-EU Modem didn’t work on some passive FTP servers with TLS security and firewall settings
V4.7 B1 (12-1-2023)
– Swarm satellite -> Camera picture sending on alarm, digital trigger or on daily basis
– Calculated channels driver -> Functions “or”, “and”, “xor” and parameter alarm status (ALR) added
– General settings -> Option added for instant data log and output on startup or configuration change (default is off)
– Wifi driver -> HTTP Azure-IoT SAS enabled
– All output drivers -> Send delay’s will also be used when alarm mode is active
– SDI12 sensor driver -> 10 msec inter command delay added to cope with slow acting sensors
– Hardware watchdog feature enabled in addition to the various existing software watchdogs
– Power sensor -> Code added to support both INA234 & INA219 power sensors
V4.6 B11 (14-10-2022)
– Work-around Swarm driver -> Swarm anti-stall function implemented.
– Work-around Modem driver -> Made auto IPv4/IPv6 selection an optional feature to avoid issues when resolving domain names.
– Bug fix MQTT driver -> SparkplugB aliases were not system wide unique.
– Bug fix Modem driver -> Internet activation procedure adapted to cope with changes to the FTP stack of the latest ME910G1 modem FW.
V4.6 B9 (9-9-2022)
– Camera driver -> Pictures taking on log interval and/or at any alarm and/or at digital trigger
– SSL/TLS security -> TLS V1.3 support added for ME910G1 Modems
– FTP driver -> FTP transfer closing eased to cope with long (NB-IoT) latencies to avoid file truncation
– Bug fix remote connection -> Deadlock solved when entering Modem settings menu while connected remotely (also via wifi)
– Bug fix USB interface -> Incidental repeated watchdog reset in operational mode with USB cable unattended connected to PC is solved
V4.6 B5 (1-8-2022)
– Code adapted to support 4G modem LE910C1-EU (ML-E417)
– Code improved for Bluetooth user interface option board (ML-OU-BLE)
– Code improved for aggregation functions (double precision floating point calculations used instead of single precision)
– FTP driver -> File size verification optimized by resending file in case of premature connection loss when checking file size
– Bug fix Wifi driver -> 4 seconds delay added before server connection to avoid connection errors and retries
– Modem IP protocol -> Automatic selection for IPV4V6 disabled when 4G Modem is on fixed 2G/3G or on fallback modes
V4.6 B4 (28-6-2022)
– Bug fix Wifi driver -> Warm up time enlarged from 2 to 3 seconds (latest uBlox wifi modules need more warm up).
– Bug fix Modem driver -> Incidental Modem driver lock up due to incidental missing transmit completed interrupt
V4.6 B2 (8-6-2022)
– Configuration -> Feature added to upload partial configuration changes by means of small JSON objects (snippets).
– Modem driver -> IPv6 enabled (Automatic selection between IPv4/6).
– Modem driver -> SNI(Server Name Indication) for ML-417 enabled.
– Modem driver -> CHAP AUTH2 enabled.
– GPS driver -> Feature added to calculate drift in meters from deployment position.
– FTP driver -> Feature added to read input parameters by FTP.
– BLE driver -> Code improved to handle unexpected connection loss during configuration.
V4.5 B2 (14-4-2022)
– FTP driver -> OTA configuration update and firmware upgrade feature added.
– MQTT driver -> Sparkplug-B data format option added.
– MQTT driver -> Client ID length increased from 23 to 47 characters.
– MODBUS driver -> Feature added to perform an (occasional) maintenance command (e.g. a wiper action).
– Battery (protection & lifespan) -> LiFePO4 battery overcharge protection enhanced.
– Option boards -> Board to board communication performance improved.
V4.4 B6 (1-12-2021)
– SD card clock speed increased for logging at 10 Hz to reduce data gaps
– Swarm satellite modem driver improved to reduce power consumption
– Bug fix for high speed aggregations and alarm sampling regarding high power consumption
– Bug fix ML-OI-COM-RS485 drivers -> Code improved by fast switching to receive mode to avoid losing first bytes from fast responding devices
– Bug fix Wifi output driver -> MQTT stalled when publishing firmware upgrade or configuration uploads via option board (ML-OA-WIFI)
V4.4 B4 (30-9-2021)
– FTP driver -> File transfer verification can be switched-off for systems instantly processing/deleting/moving transfered files.
– Modem/WiFi output drivers -> Repetitive transfers in chunks when exceeding max payload setting.
– Modem settings -> Option added (FWSWITCH) to load custom FW for AT&T (US), Verizon (US) or Telstra (AU) if applicable.
– Bug fix output drivers -> Drivers enhanced to avoid occasional transfer errors with 100K+ files due to wrong size reports.
– Bug fix FTP driver -> Driver enhanced to avoid occasional file truncation for ML-417’s with ME910C1-WW modem.
– Bug fix Modem driver -> Warm-up time enlarged to avoid occasional SIM errors for ML-417’s with ME910C1-WW modem.
V4.4 B3 (1-9-2021)
– Maintenance menu -> Option added to be able to perform a remote (GSM/WiFi/BLE) reboot of the logger and option boards
– WiFi output driver -> WiFi routers scan added (ML-OA-WIFI, WiFi accessory output board)
– Improved Bluetooth LE connection handling (ML-OU-BLE, wireless user interface board)
V4.4 B1 (14-7-2021)
– Driver added for PT1000 thermistors input board (ML-OI-AD-PT1000)
– Digital pulse input driver -> Option added to set 1 msec anti bounce filter (only for low frequency pulses)
– Digital state input driver -> Option added to log each state change event (in previous versions it was always on)
– Network signal sensor driver -> Parameters “Radio channel code” (ARFCN) and “Operator PLMN code” added
– Quicker startup -> You don’t have to wait for Modem to be ready before entering the Menu’s
– Bug fix FTP driver -> 10 msec delay added prior to FTPOPEN command for ME910C1-WW modem to avoid “context not opened” error
V4.3 B10 (27-5-2021)
Attention
– Bug fix to avoid parasitic power drawn from SD-cards while in sleep. This bug, impacting the battery life of LI and 3LI powered data loggers, was introduced in FW 4.1B2.
V4.3 B9 (14-5-2021)
– Modem settings -> NB-IoT technology for ML-417 enabled.
– Bug fix FTP driver -> FTP terminal link request timeout enlarged to accommodate to high network latencies.
– Bug fix calculated channels driver -> Parameter attribute AGE incorrectly stopped counting on a sensor timeout (WDT).
– Bug fix aggregated channels driver -> Wrong aggregation period evaluation, introduced since V4.2B2 due to adding the “Percentage of change” and “Rate of change” parameters.
– Bug fix SDI12 sensor driver -> Skipping the break signal when sensors are sending a break signal before responding to aDx! commands.
V4.3 B3 (5-3-2021)
– HTTP driver -> “Connection: keep-alive” added to HTTP headers to prevent premature disconnects by a HTTP-server before receiving its response.
– Output drivers -> Random send delay option added (in addition to the fixed send delay) to ease out server load, preventing data loggers to connect all simultaneously.
V4.3 B1 (17-2-2021)
– Com port tunnel driver added for MQTT pass-through commands
– Swarm satellite modem driver added for accessory board (ML-AB-TILE)
– MODBUS sensor driver -> Data type floating point double precision (8 bytes IEEE 754) added
– General settings -> Option added to select used power supply board
V4.2 B5 (5-1-2021)
– APN registration -> Modem stored APN (CGDCONT) checked and rewritten/cleared when necessary only
V4.2 B5 (21-12-2020)
– General settings -> Deployment end date and time added to suspend all operations
– HTTP driver -> Azure-IoT Shared Access Token authorization added
– Bug fix ML-OA-RS232 drivers -> Power control switch for ML-OP-524 was switched off directly after warm up was finished (affected versions FW4.x)
– Bug fix internal sensors driver -> Preventing firmware to hang when internal voltage/current sensor is broken
– Bug fix -> Calculations & Aggregations did not work properly for parameters with an independent log interval
V4.2 B3 (12-11-2020)
– Aggregated channels driver -> “Percentage of change” and “Rate of change (unit/h)” parameters added
– Auxiliary input/output boards -> Possibility enabled to allow a board to read its settings from the logger configuration storage, making board exchange or mass deployment easy
– Send delay will be skipped on data alarm, digital alarm or digital trigger when “Direct data output on data alarm” is set
– JSON data format -> IMEI number and SIM ID added at the “device” line when send by Modem
– Bug fix TCP terminal tunnel -> Data exchange timeout for Modem enlarged from 90 sec to 3 minutes
– Bug fix auxiliary output boards (ML-OO) -> Don’t wait for parameters with independent data log interval to be updated
V4.2 B1 (12-10-2020)
– SDI12 sensor driver -> Option added to send “wake up preambles” for sensors with low power sleep mode
– Digital pulse and state driver -> Daily counter reset adjusted on a minute basis
– MQTT driver -> Option added to omit subtopics
– Email driver -> Alarm emails and data emails enabled for LE910-AP and ME910G1-W1 Modems (data in body only)
– Email driver -> Data container option added (email body (max 1500 bytes) or email attachment)
– FTP driver -> Option added to enable file size verification for FTP servers that does not delete files too quickly (at least 3 seconds required)
– All output drivers -> Send delay will be skipped when alarm mode is active
– Bug fix remote login -> The logger may hang when accessing the Modem settings menu remotely
V4.1 B4 (07-08-2020)
– Bug fix RS485 -> Port modes “RS485 8N2” and “RS485 7E1” did not work
– SD Card test -> Manufacturer ID, OEM ID and product name added
V4.1 B2 (22-07-2020)
– Data output flags added, to specify the data output(s) for a Parameter (Modem, Wifi, Satellite, Radio, ASCII, Auxiliary (OB1/OB2)
– Display driver -> Flashing patience text “Retrieving Data” when building a trend (max 30s).
– FTP driver -> CID id added to AT#FTPOPEN for ME910C1-WW Modem using Verizon
– Code adapted to support 4G modem ME910G1 (ML-417 without 2G fallback)
V4.0 B7 (5-06-2020)
FTP driver -> Modification to cope with FTP servers that removes the data file immediately after transfer while data logger still busy verifying transferred file size
V4.0 B6 (2-06-2020)
– Improved SD-card handling
– Calculated channels driver -> Parameter attribute .AGE added (seconds since last successful measurement)
– Camera driver -> Daily operating time slot added (e.g to take pictures during day light only)
– Battery (protection & lifespan) -> Rechargeable LFP (LiFePo4) batteries added
– Users & Rights option added instead of only one local password
– Driver added for auxiliary output boards (ML-OO)
– Port selection “4..20 mA” added for analog option board ML-OI-AD-20mA
– Digital pulse and trigger drivers -> Option added to trigger also on rising edge (previous it was only falling edge)
– Parameter overview menu reorganized with direct parameter editing and sorting
– Parameter data transpond setting changed in data output flags with flag options: Modem, Wifi, Satellite, Radio, ASCII, Auxiliary (OB1/OB2)
For more history of version changes please view the articles below: