When using SCPI over serial (over USB), we want the header without waiting
for the terminating newline, as otherwise the transfer may time out.
sr_scpi_get_data() will block until the message is complete.
Lowlevel access functions should not alter the data. sr_scpi_get_string(),
which is called by most highlevel access functions, strips newlines
in a central place, and is only fed with data which contains newlines
as a final terminator.
IEEE 488.2 definite length blocks may contain arbitrary data, thus the
payload up to the provided length should be passed unaltered.
Track if the last received character is a newline, which can be used
by sr_scpi_get_string() and its callers to determine if the response
is complete.
g_get_monotonic_time() returns current time in microseconds, use the same
granularity for storing the read timeout.
There is also no need to check the timeout if data has just been read.
When nothing was received in a read attempt, we need not adjust the
buffered data's read position nor the glib string object's size. Skip
any processing for empty input, just keep checking for timeouts.
Routine sr_scpi_get_data() checks for free space in the receive buffer,
and resizes the buffer when free space drops below a threshold. The
previous logic assumed that the resize and the read logic would interact
in some specific way to achieve the desired operation.
Adjust the buffer resize such that more free space is pre-allocated, yet
the payload size of the buffer is not affected. This eliminates the
dependency of the optional resize logic from subsequent activity for
reception of data that is non-optional.
Add comments while we are here, outline the steps taken in the
sr_scpi_get_data() routine.
Undo the change which skips management activities when no data was
received. This change breaks the current implementation, and needs to
get deferred until a delicate interaction between the resize and the
read logic has been eliminated.
Slightly rephrase the SCPI code which parses the responses that carry
(binary) data blocks. Be explicit about NUL termination when parsing the
leading length spec in the response, obsoleting the array initializer.
Add lots of comments and group source code lines to better reflect
what's happening from the protocol's perspective.
Fix the returned error code in the path which reads responses of
excessive length in chunks. The previous implementation detected errors
but always returned code 0 (success).
When nothing was received in a read attempt, we need not adjust the
buffered data's read position nor the glib string object's size. Skip
any processing for empty input, just keep checking for timeouts.
Drop an initial assignment to a variable which never takes effect.
Add braces around the body of a more complex if block. Separate routines
from each other by exactly one empty line.
Binary block data is specified in IEEE 488.2. First character is '#',
followed by a single ascii digit denoting the the number of digits needed
for the length specification. Length is given in bytes.
This allows drivers to replace retrieval of comma separated ASCII values
with binary formats. See bug #791.
While some transports add a terminating (carriagereturn+)linefeed
unconditionally, the USBTMC transport does not. At least the R&S HMO1002
requires the linefeed and locks up otherwise. Fixes bug #784.
This changes the TCP and VXI transport from CR+LF to LF only.
Also fixes a possible memory leak for VXI, where the temporary command
buffer was not freed in case of a write error.
According to USBTMC usb488 subclass spec, wValue hast to be 0 for both
LOCAL_LOCKOUT and GO_TO_LOCAL. At least required for R&S HMO1002, the
bad request results in a STALL. Fixes bug #783.
Devices connected on a real GPIB bus are placed in remote mode when
opening them. libgpib does not automatically place devices back in
local mode when closing the handle. It is thus possible to lock out a
GPIB device by probing it with libsigrok.
This happens on the HP 3457A meter, which does not have a "LOCAL"
command, and must be put back in local mode via GPIB handshake.
ibloc() takes care of this, and it does it on a per-device basis,
such that other devices on the GPIB bus are not affected.
libgpib has an error_string which formats a numeric error code into a
human-readable description. Use that instead of printing the numeric
code, as it makes debugging easier.
This fixes parts of bug #423.
The list of fixed warnings:
src/output/srzip.c:285:3: warning: Value stored to 'ret' is never read
ret = zip_append(o, logic->data, logic->unitsize, logic->length);
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
src/scpi/scpi.c:610:2: warning: Value stored to 'ret' is never read
ret = SR_OK;
^ ~~~~~
src/scpi/scpi.c:667:2: warning: Value stored to 'ret' is never read
ret = SR_OK;
^ ~~~~~
src/dmm/vc870.c:410:2: warning: Value stored to 'info_local' is never read
info_local = (struct vc870_info *)info;
^ ~~~~~~~~~~~~~~~~~~~~~~~~~
src/hardware/conrad-digi-35-cpu/api.c:130:2: warning: Value stored to 'ret' is never read
ret = SR_OK;
^ ~~~~~
src/hardware/fx2lafw/api.c:658:2: warning: Value stored to 'timeout' is never read
timeout = fx2lafw_get_timeout(devc);
^ ~~~~~~~~~~~~~~~~~~~~~~~~~
src/hardware/gmc-mh-1x-2x/protocol.c:941:3: warning: Value stored to 'retc' is never read
retc = SR_ERR_ARG;
^ ~~~~~~~~~~
src/hardware/gmc-mh-1x-2x/api.c:168:2: warning: Value stored to 'model' is never read
model = METRAHIT_NONE;
^ ~~~~~~~~~~~~~
src/hardware/ikalogic-scanalogic2/api.c:325:2: warning: Value stored to 'ret' is never read
ret = SR_OK;
^ ~~~~~
src/hardware/openbench-logic-sniffer/api.c:185:3: warning: Value stored to 'devc' is never read
devc = sdi->priv;
^ ~~~~~~~~~
src/hardware/rigol-ds/api.c:813:3: warning: Value stored to 'devc' is never read
devc = sdi->priv;
^ ~~~~~~~~~
src/hardware/scpi-pps/api.c:405:2: warning: Value stored to 'ret' is never read
ret = SR_OK;
^ ~~~~~
src/hardware/yokogawa-dlm/api.c:239:2: warning: Value stored to 'ret' is never read
ret = SR_ERR_NA;
^ ~~~~~~~~~
Firmware versions starting with 00.02.04 apparently cause the in and out
bulk endpoints to end up in a HALT state. This is likely related to the
larger transfer size quirk implemented in the Linux kernel for the Rigol
DS1000: this USBTMC implementation does not have that workaround.
Instead, if the firmware version is >= 00.02.04, both endpoints have the HALT
condition cleared on device close.
This fixes bug #354.
scpi-pps at line 212 assumes that an SR_OK return means that the gvar
is valid, which leads to the following error:
** GLib:ERROR:/build/glib2.0-2.45.8/./glib/gvarianttypeinfo.c:184:g_variant_type_info_check: assertion failed: (0 <= index && index < 24)
Since Autoconf places some important feature flags only into the
configuration header, it is necessary to include it globally to
guarantee a consistent build.
A few of these were pretty serious, like missing arguments,
passing integers where a string was expected, and so on.
In some places, change the types used by the code rather than
just the format strings.
There was a problem in scpi_serial.c in the scpi_serial_read_data()
function. Incoming data was written at the read position in the buffer,
although it should be written at the count position in the buffer.
Make vxi.h the first #include in all affected files and #undef the
_POSIX_C_SOURCE macro in vxi.h.
This avoids various build issues on e.g. FreeBSD or Mac OS X where
setting _POSIX_C_SOURCE leads to the unavailability of certain types
such as u_long (as used in the VXI/RPC code).
Uwe Hermann
Sven Schnelle
Stefan Brüns
Gerhard Sittig
Alexandru Gagniuc
Soeren Apel
Martin Ling
Aurelien Jacobs
Bert Vermeulen
Daniel Elstner
Martin Lederhilger