Wiki source code of LX3V-4AD

Last modified by Devin Chen on 2024/11/27 15:04

version	line-number	content
1.1	1	= 1 Introduction =
	2
	3	* The LX3V-4AD special module has four input channels. The input channels receive analog signals and convert them into a digital value. This is called an A/D conversion; the maximum resolution is 16 bits.
	4	* The selection of voltage or current based input/output is by user wiring. Analog ranges of -10 to 10V DC (resolution: 5mV), and/or 4 to 20mA, -20 to 20mA (resolution: 20µA) may be selected.
	5	* Data transfer between the LX3V-4AD and the LX3V main unit is by buffer memory exchange. There are 32 buffer memories (each of 16 bits) in the LX3V-4AD.
	6	* LX3V-4AD consumes 5V voltage from LX3V main unit or active extension unit, 90mA current of power supply.
	7
	8	= 2 Dimensions =
	9
	10	(% style="text-align:center" %)
3.1	11	[[image:LX3V-4AD_html_5159808b9e4fa86a.png\|\|height="391" width="1000" class="img-thumbnail"]]
1.1	12
11.1	13	1. (((
	14	Extension cable and connector
	15	)))
	16	1. (((
	17	COM LED: Light when communicating Error LED: Channel calibration indicators
	18	)))
	19	1. (((
	20	Power LED: Light when connect to 24V
	21	)))
	22	1. (((
	23	State LED: Light when normal condition
	24	)))
	25	1. (((
	26	Link LED: Light when communicate with PLC
	27	)))
	28	1. (((
	29	Module name
	30	)))
	31	1. (((
	32	Extension module interface
	33	)))
	34	1. (((
	35	DIN rail mounting slot
	36	)))
	37	1. (((
	38	DIN rail hook
	39	)))
	40	1. (((
	41	Holes for direct installation: 2 places (Φ4.5)
	42	)))
1.1	43
4.1	44	(((
11.1	45	(% style="margin-left:auto; margin-right:auto" %)
	46	\|=Name\|=Description\|=Light status\|=Event status
	47	\|(% rowspan="2" %)(((
	48	COM LED
	49
	50
	51	)))\|(% rowspan="2" %)(((
	52	Communication indicator for communication board and acquisition board
	53
	54
	55	)))\|Flashing\|Data interacting
	56	\|Off\|Data interaction error/stop/failure
	57	\|(% rowspan="2" %)(((
	58	ERR LED
	59
	60
	61	)))\|(% rowspan="2" %)(((
	62	Factory calibration LED
	63
	64
	65	)))\|Off\|Factory calibrated
	66	\|Lighting\|Factory uncalibrated
	67	\|(% rowspan="2" %)(((
	68	24V LED
	69
	70
	71	)))\|(% rowspan="2" %)(((
	72	Power indicator
	73
	74
	75	)))\|Off\|24V power is abnormal.
	76	\|Lighting\|24V power is normal.
	77	\|(% rowspan="3" %)(((
	78	LINK LED
	79
	80
	81	)))\|(% rowspan="3" %)(((
	82	Communication indicator for PLC and expansion module
	83
	84
	85	)))\|Flashing\|Data interacting
	86	\|Off\|Data interaction error/stop/failure
	87	\|Lighting\|Software running abnormal or hardware failure
	88	\|(% rowspan="3" %)(((
	89	AD LED
	90
	91
	92	)))\|(% rowspan="3" %)(((
	93	4 channel indicators
	94
	95
	96	)))\|Flashing\|Input voltage or current range exceed limit or channel unconnected
	97	\|Off\|Channel closed
	98	\|Lighting\|Input analog is in the normal range
	99
13.1	100	(% style="text-align:center" %)
	101	[[image:LX3V-4AD_html_5bc4b53029347d0f.png\|\|height="309" width="618" class="img-thumbnail"]]
12.1	102
	103
4.1	104	Please use crimp terminals as indicated on the graph.
1.1	105
4.1	106	The tightening torque should be applied 5 to 8 Kg.cm.
1.1	107
	108	= 3 Terminal layouts =
	109
	110	(% style="text-align:center" %)
4.1	111	[[image:image-20220728103451-1.png\|\|class="img-thumbnail"]]
3.1	112	)))
1.1	113
	114	(((
	115	1. The analog input is received through a twisted pair shielded cable. This cable should be wired separately from power lines or any other lines which may induce electrical noise.
	116	1. If a voltage ripple occurs during input, or there is electrically induced noise on the external wiring, connect a smoothing capacitor of 0.1 to 0.47µF, 25V.
	117	1. If you are using current input, connect the V+ and I+ terminals to each other.
	118	1. If there is excessive electrical noise, connect the FG frame ground terminal with the grounded terminal on the LX3V-4AD.
	119	1. Connect the ground terminal on the LX3V-4AD unit with the grounded terminal on the main unit. Use class 3 grounding on the main unit, if available.
	120
7.1	121	Note: when connect a 4-20ma sensor(need +24V working voltage), the wiring is as below:
	122
	123	[[image:企业微信截图_16771315134574.png]]
	124
1.1	125	= 4 Installation =
	126	)))
	127
	128	Environment specification
	129
	130	(% class="table-bordered" %)
4.1	131	\|=(% style="width: 490px;" %)Item\|=(% style="width: 585px;" %)Specification
	132	\|(% style="width:490px" %)Environmental specifications (excluding following)\|(% style="width:585px" %)Same as those for the LX3V main unit
	133	\|(% style="width:490px" %)Dielectric withstand voltage\|(% style="width:585px" %)500VAC, 1min (between all terminals and ground)
1.1	134
	135	Power supply specification
	136
	137	(% class="table-bordered" %)
4.1	138	\|=(% style="width: 294px;" %)Item\|=(% style="width: 781px;" %)Specification
	139	\|(% style="width:294px" %)Analog circuits\|(% style="width:781px" %)24V DC ± 10%, 55mA (external power supply from main unit)
	140	\|(% style="width:294px" %)Digital circuits\|(% style="width:781px" %)5V DC, 90mA (internal power supply from main unit)
1.1	141
	142	Performance specification
	143
	144	Analog Inputs
	145
9.1	146	(% style="margin-left:auto; margin-right:auto" %)
	147	\|= \|=Voltage Input\|=Current input
	148	\|=Items\|(% colspan="2" %)Either voltage or current input can be selected with your choice of input terminal. Up to four input points can be used at one time.
	149	\|=Analog input range\|(((
1.1	150	DC -10V to +10V (input resistance: 200kΩ).
	151
	152	Warning: this unit may be damaged by input voltage in excess of ±15V
9.1	153	)))\|(((
1.1	154	DC -20mA to +20mA (input resistance: 250Ω).
	155
	156	Warning: this unit may be damaged by input currents in excess of ±32mA.
	157	)))
9.1	158	\|=Digital output\|(% colspan="2" %)(((
1.1	159	12-bit conversion stored in 16-bit 2’s complement form
	160
9.1	161	Maximum value: +2047 Minimum value: -2048
1.1	162	)))
9.1	163	\|=Analog accuracy\|±1% (for the range of -10V to +10V)\|±1% (for the range of -20mA to +20mA)
	164	\|=(((
1.1	165	Conversion
	166
9.1	167	time for each channel
	168	)))\|(% colspan="2" %)Tconv ≤10ms (High-speed), 10ms≤Tconv≤20ms (Middle speed), Tconv>20ms (Low speed)
1.1	169
	170	Analog Inputs continued...
	171
	172	(% class="table-bordered" %)
4.1	173	\|=Preset 0 (-10V to +10V)\|=Preset 1 (+4mA to +20mA)\|=Preset 2 (-20mA to +20mA)
	174	\|[[image:LX3V-4AD_html_8bdc9efc08b433c8.png\|\|height="371" width="420" class="img-thumbnail"]]\|[[image:LX3V-4AD_html_a268382a2adb0b80.png\|\|height="345" width="420" class="img-thumbnail"]]\|[[image:LX3V-4AD_html_a58cfb9f37ade123.png\|\|height="363" width="420" class="img-thumbnail"]]
1.1	175
4.1	176	(% class="box infomessage" %)
	177	(((
	178	✎Note: Preset ranges are selected by an appropriate setting in buffer memory of the analog block. Current/Voltage input selection must match the correct input terminal connections.
	179	)))
1.1	180
	181	Miscellaneous
	182
	183	(% class="table-bordered" %)
4.1	184	\|=(% scope="row" style="width: 147px;" %)Item\|=(% style="width: 928px;" %)Description
	185	\|=(% style="width: 147px;" %)Isolation\|(% style="width:928px" %)(((
1.1	186	Photo-couple isolation between analog and digital circuits. DC/DC converter isolation of power from LX3VCPU.
	187
	188	No isolation between analog channels.
	189	)))
	190
	191	Allocation of buffer memories (BFM)
	192
8.1	193	(% style="margin-left:auto; margin-right:auto" %)
	194	\|=BFM\|=(% colspan="9" %)Description
	195	\|*#0\|(% colspan="9" %)Channel initialization, default=H0000
	196	\|*#1\|Channel 1\|(% colspan="8" rowspan="4" %)(((
1.1	197	Contains the number of samples (1 to 4096) to be used for an averaged result.
	198
	199	The default setting is 8-normal speed. High speed operation can be selected with a value of 1.
	200	)))
8.1	201	\|*#2\|Channel 2
	202	\|*#3\|Channel 3
	203	\|*#4\|Channel 4
	204	\|#5\|Channel 1\|(% colspan="8" rowspan="4" %)These buffer memories contain the averaged input values for the number of samples entered for the channel in buffer memories #1 to #4 respectively.
	205	\|#6\|Channel 2
	206	\|#7\|Channel 3
	207	\|#8\|Channel 4
	208	\|#9\|Channel 1\|(% colspan="8" rowspan="4" %)These buffer memories contain the present value currently being read by each input channel.
	209	\|#10\|Channel 2
	210	\|#11\|Channel 3
	211	\|#12\|Channel 4
	212	\|#13-#14\|(% colspan="9" %)Reserved
	213	\|(% rowspan="10" %)#15\|(% rowspan="10" %)(((
	214	Selection of A/D conversion speed
	215
	216	Please refer to note 2
	217	)))\|(% colspan="4" %)Set value\|(% colspan="4" %)(((
	218	Conversion time
	219
	220	(Unit: ms/channel)
	221	)))
	222	\|(% colspan="4" %)0 (Default)\|(% colspan="4" %)15
	223	\|(% colspan="4" %)1\|(% colspan="4" %)6
	224	\|(% colspan="4" %)10\|(% colspan="4" %)3
	225	\|(% colspan="4" %)11\|(% colspan="4" %)4.5
	226	\|(% colspan="4" %)12\|(% colspan="4" %)7
	227	\|(% colspan="4" %)13\|(% colspan="4" %)12.5
	228	\|(% colspan="4" %)14\|(% colspan="4" %)23.5
	229	\|(% colspan="4" %)15\|(% colspan="4" %)45.5
	230	\|(% colspan="4" %)16\|(% colspan="4" %)101
	231	\|#16-#19\|(% colspan="9" %)Reserved
	232	\|*#20\|(% colspan="9" %)Reset to Defaults and Preset. Default = 0
	233	\|*#21\|(% colspan="9" %)(((
1.1	234	Offset, Gain Adjust Prohibit.
	235
	236	Default = (0, 1) Permit
	237	)))
8.1	238	\|*#22\|Offset, Gain Adjust\|G4\|04\|G3\|03\|G2\|01\|G1\|01
	239	\|*#23\|(% colspan="9" %)Offset Value Default = 0
	240	\|*#24\|(% colspan="9" %)Gain Value Default = 5,000
	241	\|#25-#28\|(% colspan="9" %)Reserved
	242	\|#29\|(% colspan="9" %)Error status
	243	\|#30\|(% colspan="9" %)(((
1.1	244	Identification code K2010 (12-bit resolution)
	245
	246	Identification code K2011 (16-bit resolution)
	247	)))
8.1	248	\|#31\|(% colspan="9" %)Hardware version
1.1	249
10.1	250	(% class="box infomessage" %)
	251	(((
	252	✎Note:
	253
1.1	254	* In buffer memory locations (BFM’s) marked with an “*” data can be written from the PC using the TO command.
	255	* For buffer memories (BFM’s) without “*”mark, data can be read to the PC using the FROM command.
	256	* Before reading from the analog special function block, ensure these settings have been sent to the analog special function block. Otherwise, the previous values held in the analog block will be used.
	257	* Offset (intercept): The analog input value when the digital output becomes 0.
	258	* Gain (slope): The analog input value when the digital output becomes +1000.
4.1	259	)))
1.1	260
4.1	261	Channel Selection
1.1	262
	263	Channel initialization is made by a 4 character HEX number HOOOO in buffer memory BFM #0. The least significant character controls channel 1 and the 4 character controls channel4.
	264
	265	(% class="table-bordered" %)
4.1	266	\|=(% scope="row" %)BFM#0\|=Analog input\|=Digital output\|=Resolution\|=Offset/Gain\|=Constant
	267	\|=0\|-10V~~10V\|-2000~~2000\|5 mV\|0/5000\|1000
	268	\|=1\|4mA~~20mA\|0~~1000\|16µA\|4000/20000\|1000
	269	\|=2\|-20mA~~20mA\|-1000~~1000\|20µA\|0/20000\|1000
	270	\|=3\|Disabled\|/\|/\|/\|/
	271	\|=4\|-10V~~10V\|-10000~~10000\|1mV\|0/5000\|10000
	272	\|=5\|4 mA ~~20mA\|0~~10000\|1.6µA\|4000/20000\|10000
	273	\|=6\|-20mA~~20mA\|-10000~~10000\|2.0µA\|0/20000\|10000
1.1	274
	275	Example: H3310
	276
4.1	277	* CH1: Preset range (-10V to +10V).
	278	* CH2: Preset range (+4mA to +20mA).
	279	* CH3, CH4: Channel OFF.
1.1	280
4.1	281	Analog to Digital Conversion Speed Change
1.1	282
8.1	283	By writing 0, 1 or decimal numbers between 10-16 into BFM#15 of the LX3V-4AD, the time at which A/D conversion is performed can be changed.
1.1	284
8.1	285	However, the following points should be noted:
1.1	286
8.1	287	1. To maintain a high-speed conversion, please use the FROM/TO commands as seldom as possible.
	288	1. When a conversion speed change occurs, BFM #1-#4 are set to their default values immediately after the change. Please be careful if an A/D time conversion will be part of the normal program execution.
	289	1. High-speed time conversion is usually used with BFM#1-#4.
	290	1. BFM#15 is configurated with the corresponding conversion time of 10-16, only supported by software version 20000 or above.
1.1	291
	292	Adjusting Gain and Offset values
	293
	294	*Formula for Gain/Offset: Digital output= (Analog input-Offset)Constant/ (Gain-Offset)**
	295
	296	* When buffer memory BFM #20 is activated by setting it to K1, all settings within the analog special function block are reset to their default settings. This is a very quick method to erase any undesired gain and offset adjustments.
	297	* If (b1, b0) of BFM #21 is set to (1, 0), gain and offset adjustments are prohibited to prevent inadvertent changes by the operator. In order to adjust the gain and offset values, bits (b1, b0) must be set to (0, 1). The default is (0, 1).
	298	* Gain and offset values of BFM #23 and #24 are sent to non-volatile memory gain and offset registers of the specified input channels. Input channels to be adjusted are specified by the appropriate G-O (gain-offset) bits of BFM #22.
8.1	299	* (((
	300	Example:
1.1	301
8.1	302	If bits G1 and O1 are set to 1, input channel 1 will be adjusted when BFM #22 is written to by a TO instruction.
	303	)))
	304	* Channels can be adjusted individually or together with the same gain and offset values.
	305	* Gain and offset values in BFM #23 #24 are in units of mV or µA. Due to the resolution of the unit the actual response will be in steps of 5mV or 20µA.
	306	* When gain is less than or equal to offset, error will be adjusted. Gain and offset will not change. Error status will be given at BFM#29 b1. B4-b7 will give a specific channel offset/gain error.
	307
1.1	308	Example:
	309
	310	If bits G1 and O1 are set to 1, input channel 1 will be adjusted when BFM #22 is written to by a TO instruction.
	311
	312	* Channels can be adjusted individually or together with the same gain and offset values.
	313	* Gain and offset values in BFM #23 #24 are in units of mV or µA. Due to the resolution of the unit the actual response will be in steps of 5mV or 20µA.
	314
	315	Status Information BFM #29
	316
8.1	317	(% style="margin-left:auto; margin-right:auto" %)
	318	\|=Bit devices of BFM #29\|=ON\|=OFF
	319	\|b0: Error\|When any of b1 to b4 is ON. If any of b2 to b4 is ON, A/D conversion of all the channels is stopped\|No error
	320	\|b1: Offset/gain error\|Offset/Gain data in EEPROM is corrupted or adjustment error.\|Offset/Gain data normal
	321	\|b2: Power source abnormality\|24V DC power supply failure\|Power supply normal
	322	\|b3: Hardware error\|A/D converter or other hardware failure\|Hardware normal
9.1	323	\|b4: Channel 1 offset/gain error\|(% rowspan="4" %)When channel offset/gain error is modified, the corresponding position is ON.\|(% rowspan="4" %)Offset/Gain adjustment normal
8.1	324	\|b5: Channel 2 offset/gain error
	325	\|b6: Channel 3 offset/gain error
	326	\|b7: Channel 4 offset/gain error
	327	\|b10: Digital range error\|Digital output value is less than -2048 or more than +2047\|Averaging is normal. (Between 1 and 4096)
	328	\|b11: Averaging error\|Number of averaging samples is 4097 or more or 0 or less (default of 8 will be used)\|Averaging is normal. (Between 1 and 4096)
	329	\|b12: Adjust prohibit\|Prohibit-(b1, b0) of BFM #21 is set to (1, 0)\|Permit-(b1, b0) of BFM #21 is set to (0,1)
1.1	330
15.1	331	(% class="box infomessage" %)
	332	(((
9.1	333	✎Note: b8, b9 and b13 to b15 are undefined.
15.1	334	)))
1.1	335
	336	Identification Code BFM #30
	337
	338	The identification (or ID) code number for a Special Function Block is read using the FROM command.
	339
	340	This number for the LX3V-4AD unit is K2011 or K2010.
	341
	342	The user’s program in the PC can use this facility in the program to identify the special function block before commencing data transfer from and to the special function block.
	343
15.1	344	(% class="box infomessage" %)
	345	(((
1.1	346	✎Note:
	347
	348	* Values of BFM #0, #23 and #24 are copied to EEPROM memory of the LX3V-4AD. BFM #21 and BFM #22 are only copied when data is written to the gain/offset command buffer BFM #22. Also, BFM #20 causes writing to the EEPROM memory. The EEPROM has a life of about 10,000 cycles (changes), so do not use programs which frequently change these BFMs.
	349
	350	* Because of the time needed to write to the EEPROM memory, a delay of 300 ms is required between instructions that cause a write to the EEPROM. Therefore, a delay timer should be used before writing to the EEPROM a second time.
15.1	351	)))
1.1	352
	353	= 5 Defining gain and offset =
	354
	355	Gain determines the angle or slope of the calibration line, identified at a digital value of 1000.
	356
4.1	357	* (a) Small gain: Large steps in digital readings
	358	* (b) Zero gain: Default is 5V or 20mA.
	359	* (c) Large gain: Small steps in digital readings.
1.1	360
	361	Offset is the “Position” of the calibrated line, identified at a digital value of 0.
	362
4.1	363	* (d) Negative offset.
	364	* (e) Zero offset: Default is 0V or 4mA.
	365	* (f) Positive offset.
1.1	366
	367	(% style="text-align:center" %)
4.1	368	[[image:LX3V-4AD_html_f78533c1d988f63f.png\|\|height="298" width="800" class="img-thumbnail"]]
1.1	369
	370	Offset and gain can be set independently or together. Reasonable offset ranges are -5 to +5V or -20mA to 20mA, and gain values 1V to 15V or 4mA to 32mA. Gain and offset can be adjusted by software in the LX3V main unit (please refer to program example 2).
	371
9.1	372	* Bit device’s b1, b0 of the gain/offset BFM #21 should be set to 0, 1 to allow adjustment.
1.1	373	* Once adjustment is complete these bit devices should be set to 1, 0 to prohibit any further changes.
	374	* Channel initialization (BFM #0) should be set to the nearest range, i. e. voltage/current etc.
	375
	376	= 6 Example program =
	377
4.1	378	Basic program
1.1	379
10.1	380	In the following example channels CH1 and CH2 are used as voltage inputs. The LX3V-4AD block is connected at the position of special function block No.0. Averaging is set at 4 and data registers D0 and D1 of the PC receive the averaged digital data. The FROM code for the special function block at position “0" is read from BFM #30 of that block and stored at D4 in the main unit. CMP is compared to check the block is a LX3V-4AD, if OK M1 is turned ON.
1.1	381
10.1	382	[[image:LX3V-4AD_html_e3a9b9608260f138.png\|\|height="297" style="float:left" width="600" class="img-thumbnail"]]
1.1	383
	384	✎Note:
	385
	386	1. TO code: The analog input channels (CH1, CH2) are setup by writing H3300 to BFM #0 of the LX3V-4AD
	387	1. The number of averaged samples for CH1 and CH2 is set to 4 by writing 4 to BFM #1 and #2 respectively.
	388	1. The operational status of the LX3V-4AD is read from BFM #29 and output as bit devices at the LX3V main unit. If there are no errors in the operation of the LX3V-4AD, then the averaged data BFM’s are read.
	389	1. In the case of this example BFM #5 and #6 are read into the LX3V main unit and stored at D0 and D1. These devices contain the averaged data for CH1 and CH2 respectively.
	390
	391	Using gain and offset in a program
	392
	393	The gain and offset of the LX3V-4AD can be adjusted using push-button switches on the input terminal of the PC. It can also be adjusted using software settings sent from the PC.
	394
	395	Only the gain and offset values in the memory of the LX3V-4AD need be adjusted. A voltmeter or an ammeter for the analog input is not needed. A program for the PC will be needed however.
	396
	397	The following is an example of changing the offset value on input channel CH1 to 0V and the gain value to 2.5V.
	398
	399	The LX3V-4AD block is in the position of block No.0 (i.e. closest to the LX3V main unit).
	400
	401	Example: Adjusting gain/offset via software settings
	402
	403	(% style="text-align:center" %)
4.1	404	[[image:LX3V-4AD_html_41bef52ee180f2c9.png\|\|height="980" width="600" class="img-thumbnail"]]
1.1	405
	406	(((
	407	Adjustment start
	408
4.1	409	* (H0000)->BFM#0 (initialize input channels). Enter the instructions on the left and RUN the PC
	410	* (K1)->BFM#21. BFM#21 must be set to permit with (b1, b0)=(0,1)
	411	* (K0)->BFM#22 (offset/gain adjusts). Reset adjust bits
	412	* (K0)-> BFM#23 (offset)
	413	* (K2500)-> BFM#24 (gain)
	414	* (H0003)->BFM#22(offset/gain adjusts). 3=0011 i.e. O1=1, G1=1. Therefore channel 1 is adjusted.
1.1	415
	416	Adjustment ends.
	417
	418	(K2)-> BFM#21. BFM#21 gain/offset adjust prohibit
8.1	419
	420	High-speed conversion by changing A/D conversion time in a program
	421
16.1	422	[[image:6.3-图片1.png]]
1.1	423	)))
	424
8.1	425	Writing K10 to BFM#15 and set conversion time of all channels as 3ms.
	426
	427	Writing 1 to BFM#1 and set Channel 1 sample count to 1 to Channel 1 high-speed conversion.
	428
1.1	429	= 7 Diagnostics =
	430
	431	Preliminary checks
	432
	433	1. Check whether the input wiring and/or extension cables are properly connected on LX3V-4AD analog special function block.
	434	1. Check that the LX3V system configuration rules have not been broken, i.e. the number of special function blocks does not exceed 8 and the total system I/O is equal or less than 256 I/O.
	435	1. Ensure that the correct operating range has been selected for the application.
	436	1. Check that there is no power overload on either the 5V or 24V power sources, remember the loading on a LX3V main unit or a powered extension unit varies according to the number of extension blocks or special function blocks connected.
	437	1. Put the LX3V main unit into RUN.
	438
	439	Error checking
	440
4.1	441	If the LX3V-4AD special function block does not seem to operate normally, check the following items.
1.1	442
	443	Check the status of the POWER LED.
	444
	445	Lit: The extension cable is properly connected.
	446
	447	Otherwise: Check the connection of the extension cable.
	448
	449	* Check the external wiring.
	450	* Check the status of the “24V” LED (top right corner of the LX3V-4AD).
	451
	452	Lit: LX3V-4AD is OK; 24V DC power source is OK.
	453
	454	Otherwise: Possible 24VDC power failure, if OK possible LX3V-4AD failure.
	455
	456	* Check the status of the “A/D” LED (top right corner of the LX3V-4AD).
	457
	458	Lit: A/D conversion is proceeding normally.
	459
	460	Otherwise: Check buffer memory #29 (error status). If any bits (b2 and b3) are ON, then this is why the A/D LED is OFF.