1Framework for Maintaining Common National Instruments Terminal/Signal names
2
3The contents of this directory are primarily for maintaining and formatting all
4known valid signal routes for various National Instruments devices.
5
6Some background:
7 There have been significant confusions over the past many years for users
8 when trying to understand how to connect to/from signals and terminals on
9 NI hardware using comedi. The major reason for this is that the actual
10 register values were exposed and required to be used by users. Several
11 major reasons exist why this caused major confusion for users:
12
13 1) The register values are _NOT_ in user documentation, but rather in
14 arcane locations, such as a few register programming manuals that are
15 increasingly hard to find and the NI-MHDDK (comments in in example code).
16 There is no one place to find the various valid values of the registers.
17
18 2) The register values are _NOT_ completely consistent. There is no way to
19 gain any sense of intuition of which values, or even enums one should use
20 for various registers. There was some attempt in prior use of comedi to
21 name enums such that a user might know which enums should be used for
22 varying purposes, but the end-user had to gain a knowledge of register
23 values to correctly wield this approach.
24
25 3) The names for signals and registers found in the various register level
26 programming manuals and vendor-provided documentation are _not_ even
27 close to the same names that are in the end-user documentation.
28
29 4) The sets of routes that are valid are not consistent from device to device.
30 One additional major challenge is that this information does not seem to be
31 obtainable in any programmatic fashion, neither through the proprietary
32 NIDAQmx(-base) c-libraries, nor with register level programming, _nor_
33 through any documentation. In fact, the only consistent source of this
34 information is through the proprietary NI-MAX software, which currently only
35 runs on Windows platforms. A further challenge is that this information
36 cannot be exported from NI-MAX, except by screenshot.
37
38
39
40The content of this directory is part of an effort to greatly simplify the use
41of signal routing capabilities of National Instruments data-acquisition and
42control hardware. In order to facilitate the transfer of register-level
43information _and_ the knowledge of valid routes per device, a few specific
44choices were made:
45
46
471) The names of the National Instruments signals/terminals that are used in this
48 directory are chosen to be consistent with (a) the NI's user level
49 documentation, (b) NI's user-level code, (c) the information as provided by
50 the proprietary NI-MAX software, and (d) the user interface code provided by
51 the user-land comedilib library.
52
53 The impact of this choice implies that one allows the use of CamelScript names
54 in the kernel. In short, the choice to use CamelScript and the exact names
55 below is for maintainability, clarity, similarity to manufacturer's
56 documentation, _and_ a mitigation for confusion that has plagued the use of
57 these drivers for years!
58
592) The bulk of the real content for this directory is stored in two separate
60 collections (i.e. sub-directories) of tables stored in c source files:
61
62 (a) ni_route_values/ni_[series-label]series.c
63
64 This data represents all the various register values to use for the
65 multiple different signal MUXes for the specific device families.
66
67 The values are all wrapped in one of three macros to help document and
68 track which values have been implemented and tested.
69 These macros are:
70 V(<value>) : register value is valid, tested, and implemented
71 I(<value>) : register value is implemented but needs testing
72 U(<value>) : register value is not implemented
73
74 The actual function of these macros will depend on whether the code is
75 compiled in the kernel or whether it is compiled into the conversion
76 tools. For the conversion tools, it can be used to indicate the status
77 of the register value. For the kernel, V() and I() both perform the
78 same function and prepare data to be used; U() zeroes out the value to
79 ensure that it cannot be used.
80
81 *** It would be a great help for users to test these values such that
82 these files can be correctly marked/documented ***
83
84 (b) ni_device_routes/[board-name].c
85
86 This data represents the known set of valid signal routes that are
87 possible for each specific board. Although the family defines the
88 register values to use for a particular signal MUX, not all possible
89 signals are actually available on each board.
90
91 In order for a particular board to take advantage of the effort to
92 simplify/clarify signal routing on NI devices, a corresponding
93 [board-name].c file must be created. This file should reflect the known
94 valid _direct_ routing capabilities of the board.
95
96 As noted above, the only known consistent source of information for
97 valid device routes comes from the proprietary National Instruments
98 Windows software, NI-MAX. Also, as noted above, this information can
99 only be visually conveyed from NI-MAX to other media. To make this
100 easier, the naming conventions used in the [board-name].c file are
101 similar to the naming conventions as presented by NI-MAX.
102
103
1043) Two other files aggregate the above data to integrate it into comedi:
105 ni_route_values.c
106 ni_device_routes.c
107
108 When adding a new [board-name].c file, be sure to also add in the line in
109 ni_device_routes.c to include this information into comedi.
110
111
1124) Several tools have been included to convert from/to the c file formats.
113 These tools are best used/demonstrated via the included Makefile targets:
114 (a) `make csv-files`
115 Creates new csv-files using content of c-files of existing
116 ni_routing/* content. New csv files are placed in csv
117 sub-directory.
118
119 As noted above, the only consistent source of information of valid
120 device routes comes from the proprietary National Instruments Windows
121 software, NI-MAX. Also, as noted above, this information can only be
122 visually conveyed from NI-MAX to other media. This make target creates
123 spreadsheet representations of the routing data. The choice of using a
124 spreadsheet (ala CSV) to copy this information allows for easy direct
125 visual comparison to the NI-MAX "Valid Routes" tables.
126
127 Furthermore, the register-level information is much easier to identify and
128 correct when entire families of NI devices are shown side by side in table
129 format. This is made easy by using a file-storage format that can be
130 loaded into a spreadsheet application.
131
132 Finally, .csv content is very easy to edit and read using a variety of
133 tools, including spreadsheets or various other scripting languages. In
134 fact, the tools provided here enable quick conversion of the
135 spreadsheet-like .csv format to c-files that follow the kernel coding
136 conventions.
137
138
139 (b) `make c-files`
140 Creates new c-files using content of csv sub-directory. These
141 new c-files can be compared to the active content in the
142 ni_routing directory.
143 (c) `make csv-blank`
144 Create a new blank csv file. This is useful for establishing a
145 new data table for either a device family (less likely) or a
146 specific board of an existing device family (more likely).
147 (d) `make clean`
148 Remove all generated files/directories.
149 (e) `make everything`
150 Build all csv-files, then all new c-files.
151
152
153
154
155In summary, similar confusion about signal routing configuration, albeit less,
156plagued NI's previous version of their own proprietary drivers. Earlier than
1572003, NI greatly simplified the situation for users by releasing a new API that
158abstracted the names of signals/terminals to a common and intuitive set of
159names. In addition, this new API provided a much more common interface to use
160for most of NI hardware.
161
162Comedi already provides such a common interface for data-acquisition and control
163hardware. This effort complements comedi's abstraction layers by further
164abstracting much more of the use cases for NI hardware, but allowing users _and_
165developers to directly refer to NI documentation (user-level, register-level,
166and the register-level examples of the NI-MHDDK).
167
168
169
170--------------------------------------------------------------------------------
171Various naming conventions and relations:
172--------------------------------------------------------------------------------
173These are various notes that help to relate the naming conventions used in the
174NI-STC with those naming conventions used here.
175--------------------------------------------------------------------------------
176
177 Signal sources for most signals-destinations are given a specific naming
178 convention, although the register values are not consistent. This next table
179 shows the mapping between the names used in comedi for NI and those names
180 typically used within the NI-STC documentation.
181
182 (comedi) (NI-STC input or output) (NOTE)
183 ------------------------------------------------------------------------------
184 TRIGGER_LINE(i) RTSI_Trig_i_Output_Select i in range [0..7]
185 NI_AI_STOP AI_STOP
186 NI_AI_SampleClock AI_START_Select
187 NI_AI_SampleClockTimebase AI_SI If internal sample
188 clock signal is used
189 NI_AI_StartTrigger AI_START1_Select
190 NI_AI_ReferenceTrigger AI_START2_Select for pre-triggered
191 acquisition---not
192 currently supported
193 in comedi
194 NI_AI_ConvertClock AI_CONVERT_Source_Select
195 NI_AI_ConvertClockTimebase AI_SI2 If internal convert
196 signal is used
197 NI_AI_HoldCompleteEvent
198 NI_AI_PauseTrigger AI_External_Gate
199 NI_AO_SampleClock AO_UPDATE
200 NI_AO_SampleClockTimebase AO_UI
201 NI_AO_StartTrigger AO_START1
202 NI_AO_PauseTrigger AO_External_Gate
203 NI_DI_SampleClock
204 NI_DO_SampleClock
205 NI_MasterTimebase
206 NI_20MHzTimebase TIMEBASE 1 && TIMEBASE 3 if no higher clock exists
207 NI_80MHzTimebase TIMEBASE 3
208 NI_100kHzTimebase TIMEBASE 2
209 NI_10MHzRefClock
210 PXI_Clk10
211 NI_CtrOut(0) GPFO_0 external ctr0out pin
212 NI_CtrOut(1) GPFO_1 external ctr1out pin
213 NI_CtrSource(0)
214 NI_CtrSource(1)
215 NI_CtrGate(0)
216 NI_CtrGate(1)
217 NI_CtrInternalOutput(0) G_OUT0, G0_TC for Ctr1Source, Ctr1Gate
218 NI_CtrInternalOutput(1) G_OUT1, G1_TC for Ctr0Source, Ctr0Gate
219 NI_RGOUT0 RGOUT0 internal signal
220 NI_FrequencyOutput
221 #NI_FrequencyOutputTimebase
222 NI_ChangeDetectionEvent
223 NI_RTSI_BRD(0)
224 NI_RTSI_BRD(1)
225 NI_RTSI_BRD(2)
226 NI_RTSI_BRD(3)
227 #NI_SoftwareStrobe
228 NI_LogicLow
229 NI_CtrA(0) G0_A_Select see M-Series user
230 manual (371022K-01)
231 NI_CtrA(1) G1_A_Select see M-Series user
232 manual (371022K-01)
233 NI_CtrB(0) G0_B_Select, up/down see M-Series user
234 manual (371022K-01)
235 NI_CtrB(1) G1_B_Select, up/down see M-Series user
236 manual (371022K-01)
237 NI_CtrZ(0) see M-Series user
238 manual (371022K-01)
239 NI_CtrZ(1) see M-Series user
240 manual (371022K-01)
241