ABB Relion COMTRADE Export: Disturbance Records From a REX610 or 615 Series

An ABB Relion record is one of the easier files to get hold of and one of the easier files to misread. The relay writes standards compliant COMTRADE into a folder you can reach with ordinary software, which removes the vendor tool bottleneck that other families impose. What it does not remove is the need to know what the numbers in the file mean, and on this platform two of them are not what an engineer reading the header would assume.

This page covers where the files live and how to pull them, the sampling arrangement that makes the binary channels coarser than they look, the unit convention on the analog channels, the naming scheme, and the memory behaviour that decides whether the record you want still exists. The specifics quoted are from the ABB REX610 technical manual, and the same disturbance recorder function, RDRE, runs across the Relion 610 and 615 families. Numbers move between products and software releases, so confirm against the manual for the relay in front of you.

Where the files are and how to get them

The relay stores COMTRADE files to a folder named COMTRADE. The manual states they can be uploaded with PCM600 or any appropriate computer software that can access that folder, which is the useful part. Unlike families where the vendor tool performs a conversion step, here the conversion has already happened inside the relay and you are collecting finished files.

One complete disturbance recording is two files. The configuration file has the .CFG extension and the data file has .DAT, and the manual is explicit that the file name is the same for both. Collect them as a pair. A .DAT without its .CFG carries no channel definitions, no scaling and no timestamps, and nothing will open it usefully.

On the IEC 61850 side the manual states that disturbance recordings are available to any Ethernet-based application in the IEC 60255-24 standard COMTRADE file format. It also states the recorder follows the 1999 version of the COMTRADE standard and uses the binary data file format, so expect a binary .DAT rather than the ASCII variety. Any parser that handles COMTRADE 1999 binary will read it.

The binary channels are coarser than the file implies

This is the detail worth carrying away from this page. The analog and binary channels in an ABB Relion record are not captured at the same rate, even though the file presents them as though they were.

The analog channels are governed by the Storage rate parameter, expressed in samples per fundamental cycle. The binary channels are not. The manual states they are sampled once per task execution of the disturbance recorder, and that the task execution interval is the same as for the protection functions. That fixes the binary sampling frequency at 200 Hz at a rated frequency of 50 Hz, and 240 Hz at 60 Hz, no matter what the analog rate is set to.

So what happens to the mismatch? The manual answers that too. During the COMTRADE conversion the digital status values are repeated so that the sampling frequencies of the analog and binary channels correspond to each other, because the COMTRADE standard requires a single rate across the file. The binary channels are upsampled by repetition to match the analog channels.

The consequence is a timing resolution question. At 32 samples per cycle on a 50 Hz system the file declares 1600 Hz, which reads as 0.625 ms per sample, but the binary channels underneath were captured at 200 Hz, which is 5 ms per sample. Each true binary sample is repeated eight times. A trip contact transition therefore lands on a 5 ms grid and is then presented on a 0.625 ms grid, and the apparent precision of that transition edge is an artifact of the repetition rather than a measurement.

If you are timing anything from a binary channel on this platform, and breaker operating time from trip assertion to current extinction is the usual case, treat the binary edge as carrying the coarser resolution. The analog channels are the ones with genuine sub millisecond timing. Current going to zero is measured at the analog rate. The trip signal that preceded it is not.

Analog values are primary peak, not secondary RMS

The second unit surprise. The manual states the analog inputs are recorded as instantaneous values and converted to primary peak value units when the relay converts the recordings to the COMTRADE format.

Two conversions are folded into that sentence. The values are referred to the primary side, so the instrument transformer ratio has already been applied and you are looking at line quantities rather than what arrived at the relay terminals. And they are peak rather than RMS, which for a sinusoid is a factor of the square root of two, about 1.414.

Relay settings are conventionally in secondary RMS. Comparing a pickup setting against a channel maximum straight out of the file therefore compares two quantities that differ by the ratio and by 1.414 together. On a 600:1 CT with a 1 A secondary pickup, the corresponding primary peak figure in the record is roughly 848 A, and an engineer who expected to see something near 600 A will conclude the record disagrees with the relay when it does not. Convert deliberately in one direction or the other before drawing any conclusion about whether an element should have operated.

A flat binary channel may just be switched off

The manual states the recording always contains all binary channels of the disturbance recorder. Disabling a channel does not remove it from the file. If one of the binary channels is disabled, its recorded state is continuously FALSE and its state changes are not recorded, and the channel name written into the configuration file becomes Unused BI.

That is a helpful marker once you know to look for it. A binary channel that sits at logical zero for the entire record means one of two very different things: a signal that was genuinely never asserted, which is evidence, or a channel that was switched off, which is the absence of evidence. The channel name in the .CFG separates them. Check the names before concluding that a protection function did not start.

The channel names themselves are worth a moment. The manual states the Channel id text parameter is used in COMTRADE configuration files as the channel identifier, and that it is user configurable in PCM600. Names in an ABB record are whatever the commissioning engineer entered, which is why channel naming quality varies so much between sites on the same relay model. The relay also writes its IP number and the Bay name parameter into the configuration file for identification, which is often the fastest way to confirm which relay a stray file came from.

The filename encodes the relay IP address

ABB uses the 8+3 character naming convention. The manual states the file name is composed of the last two octets of the relay IP number and a running counter with a range of 1 to 9999, with a hexadecimal representation used for the IP octets and the file extension appended.

Four hexadecimal characters for the two octets plus a four digit counter fills the eight character budget exactly. This is genuinely useful when files arrive without context, since the name tells you which relay produced it. It also implies a collision hazard when you collect from a fleet into a single folder. Two relays that share their last two octets on different subnets, which is common where a numbering scheme repeats per substation, will generate the same file names. Keep records in per relay folders when you gather them, or rename on collection.

Memory behaviour, and how records disappear

The maximum number of recordings is 100. The number that actually fits is computed by the relay from the memory available and the number of analog channels in use, and is readable as the remaining amount of recordings monitored data, alongside a used memory percentage. The manual gives a concrete reference point: the fixed memory allocated to the recorder fits 21 recordings of ten seconds each, holding all analog and binary channels at 32 samples per fundamental cycle.

Three behaviours decide whether the record you want is still there when you go looking.

In saturation mode captured recordings cannot be overwritten by new ones. Capture stops when the memory is full and a Memory full signal changes to TRUE. This protects history at the cost of blinding the recorder to everything after the memory filled, so a relay that saturated last month has no record of this morning. It is the opposite failure to the overwriting behaviour common on other families, and it is just as capable of leaving you without the event you need.

Deletion takes two files. The manual states the recording is not removed from the relay memory until both of the corresponding COMTRADE files, .CFG and .DAT, are deleted, and that the two may need to be deleted separately depending on the software used. Housekeeping that removes only one extension frees no memory, which is a plausible explanation for a recorder that reports itself full after someone believed they had cleared it.

Changing the pre-trigger setting destroys data. The pre-trigger time is set as a percentage of the record duration by the Pre-trg length parameter, with post-trigger time being the remainder. The manual states that changing the pre-trigger time resets the history data and the current recording under collection. Deleting all recordings at once also clears the pre-trigger recording in progress. Neither is an obvious consequence of what looks like a settings adjustment, so collect before anyone touches the recorder configuration.

What to ask for

If you are requesting an ABB Relion record from site, ask for both the .CFG and the .DAT, since they share a name and differ only by extension and one alone is unusable. Ask for the storage rate the recorder was set to, because that fixes the analog resolution and, by implication, how much of the binary channel detail is repetition. Ask for the CT and VT ratios, not to scale the record but to convert back down from primary peak when you compare against settings.

Ask whether the recorder is in saturation mode and whether the memory full signal is asserted, because on this platform a full memory means capture has stopped rather than rolled over. And if anyone is about to adjust the pre-trigger length or clear records, ask them to collect first.

Once you have the pair of files, you can open them in Detego without installing anything. It reads COMTRADE and CFF from any vendor, so an ABB Relion record, a MiCOM record and an SEL event report can be examined side by side in the same session, which is the part that matters on a mixed fleet.

Frequently asked questions

How do I get a COMTRADE file from an ABB Relion relay?

The relay writes finished COMTRADE files into a folder named COMTRADE. The manual states they can be uploaded with PCM600 or any appropriate computer software able to access that folder, so no vendor conversion step is involved. Each recording is a .CFG and a .DAT sharing one name. Over IEC 61850 the recordings are available to any Ethernet-based application in the IEC 60255-24 standard COMTRADE format.

What sample rate is an ABB Relion disturbance record?

Analog channels follow the Storage rate parameter at 32, 16 or 8 samples per fundamental cycle, giving 1600, 800 or 400 Hz at 50 Hz rated and 1920, 960 or 480 Hz at 60 Hz. Binary channels are fixed at 200 Hz or 240 Hz respectively because they are sampled once per recorder task execution, then repeated during conversion to match the analog rate.

Why do the record values not match the relay settings?

The analog channels are converted to primary peak value units during the COMTRADE conversion, while settings are normally in secondary RMS. The two differ by the instrument transformer ratio and by a factor of about 1.414 together.

What is Unused BI in an ABB COMTRADE file?

It is the channel name written for a disabled binary channel. All binary channels appear in every recording, and a disabled one is recorded as continuously FALSE with no state changes, so the name is what distinguishes a switched off channel from a signal that never asserted.

How many recordings does the relay hold?

The maximum is 100, with the practical number depending on length and channel count. The manual cites 21 recordings of ten seconds at 32 samples per cycle as the fit for the fixed recorder memory. In saturation mode capture stops rather than overwrites once full.

Why did clearing records not free any memory?

A recording is not removed from relay memory until both its .CFG and .DAT files are deleted, and depending on the software used the two may need deleting separately. Removing one extension leaves the recording in place.