EVAL Command - Expression Evaluator

Mathematical, logical, and system state expression evaluation engine.

📊Variables

V, AIN, IN, GPS, ECU...

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🧮Operators

Arithmetic, logical, bitwise

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📝Format

printf style: %d, %f, %X

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💬Examples

Practical use cases

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📋 Syntax


EVAL expression[:format[:error_value]]

Parameter	Description	Default
`expression`	Operation or query to evaluate	(required)
`format`	Output format `printf` style	`%.2f`
`error_value`	Value if evaluation fails	`ERR`

Inside the expression, arguments of multi-parameter functions are separated with ; (semicolon), not with comma. Example: ECU(0;0), MBS(1;2). The expression ends with the format separator : or with the protocol message terminator (<).

Basic Examples


>EVAL 10 + 5<

Result: 15.00


>EVAL 10 + 5.5 * 2:%.1f:NA<

Result: 21.0 (if fails, returns NA)

📊 System Variables

Without Parameters

Variable	Description	Unit
`V`	Main voltage	dV (28.0V = 280)
`VBU`	Backup battery voltage	dV
`OT`	Total odometer	meters
`OP`	Partial odometer	meters
`CREG`	Network registration status	-
`CSQ`	Cellular signal quality	0-31
`HO`	Hour meter	seconds
`VEL`	Filtered GPS speed	km/h
`HDG`	GPS heading (v1.9.18+)	0-360°
`AGE`	GPS data age	seconds
`LAT`	Latitude	degrees×10⁵
`LON`	Longitude	degrees×10⁵
`IGN`	Ignition status	0/1
`CEL`	Cellular connection	0/1
`GPS`	GPS active	0/1
`PWR`	Power supply	0/1
`JMD`	Jamming detected	0/1
`PK`	Parking	0/1
`AC`	Accelerometer	0/1
`WIF`	WiFi	0/1
`CAN`	CAN bus	0/1
`ALT`	GPS altitude	meters
`TICK`	Ticks since boot	seconds
`TT`	Internal tachometer (1 pulse/s)	0/1
`BUF`	Reports buffer has pending items	0/1
`BTHPWR`	Bluetooth power	0/1
`WIFPWR`	WiFi power	0/1
`CELPWR`	Cellular module power	0/1
`GPSPWR`	GPS module power	0/1
`VIOPWR`	Accessories power	0/1
`INTPWR`	Internal power	0/1

With One Parameter

Variable	Description	Range
`AIN(n)`	Analog input	0-3
`IN(n)`	Digital input	0-3
`XP(n)`	Digital output	0-n
`UV(n)`	User variable	0-n
`U(n)`	Auxiliary variable	0-n
`MXB(n)`	XB buffer	0-n
`DC(n)`	Angle (ANG)	0-n
`DV(n)`	Frequency (FRE)	0-n
`OW(n)`	1-Wire sensor	0-n

Event Engine signals as variables (return 0/1): In addition to those above, any indexed Event Engine trigger can be used in EVAL as TOKEN(n). Includes: ACK, AR, BE, BS, BSW, BSWN, CID, CQ, FCT, IC, ICL, KO, MC, MVXN, MVXP, MVYN, MVYP, MVZN, MVZP, NT, RG, RL, SIM, TD, TR, VL, VBU, WP, XB, ZNA, ZNB. See Trigger List for valid ranges of each one.

With Two Parameters

Variable	Description	Param 1	Param 2
`ECU(i;t)`	ECU data	Index	0=value, 2=age (ms)
`MBS(i;t)`	BLE sensors	Index	0=temp, 1=humidity
`MBSW(i;t)`	BLE wildcard	Index	0=connected, 1=major, 2=minor, 3=distance, 4=rssi, 5=age
`MDT(i;t)`	1-Wire sensor (temp)	Index	0=value, 1=age
`MTD(i;t)`	TD timers	Index	0=status, 1=timer, 2=dist, 3=timeout, 4=distanceout
`MTR(i;t)`	Trips	Index	0=trigger, 1=enabled, 2=hour, 3=minute, 4=second
`MNT(i;t)`	Counters	Index	0=current, 1=maximum
`MDL(i;t)`	LOG data	Index	0=quantity, 1=pending, 2=enabled, 3=retries, 4=retry time
`MPC(i;t)`	Pulse counter	Index	0=value, 1=factor K
`MFC(i;t)`	Frequency meter	Index	0=freq, 1=factor Q, 2=basetime

🧮 Operators

Arithmetic

Operator	Description	Example	Result
`+`	Addition	`EVAL 10 + 5`	15.00
`-`	Subtraction	`EVAL 20 - 8`	12.00
`*`	Multiplication	`EVAL 3 * 4`	12.00
`/`	Division	`EVAL 10 / 2`	5.00
`%`	Modulo (integer remainder)	`EVAL 10 % 3`	1.00

Comparators

Operator	Description	Example	Result
`gt`	Greater than	`EVAL 5 gt 3`	1.00
`lt`	Less than	`EVAL 5 lt 7`	1.00
`ge`	Greater or equal	`EVAL 5 ge 5`	1.00
`le`	Less or equal	`EVAL 4 le 5`	1.00
`eq`	Equal	`EVAL 5 eq 5`	1.00
`ne`	Not equal	`EVAL 5 ne 6`	1.00

Logical

Operator	Description	Example	Result
`&&`	Logical AND	`EVAL (5 gt 3) && (2 lt 4)`	1.00
`\|\|`	Logical OR	`EVAL (5 gt 6) \|\| (2 lt 4)`	1.00
`^^`	Logical XOR	`EVAL 1 ^^ 0`	1.00
`!`	Logical NOT (unary)	`EVAL !0`	1.00

Bitwise

Operator	Description	Example	Result
`&`	Bitwise AND	`EVAL 5 & 3`	1.00
`\|`	Bitwise OR	`EVAL 5 \| 2`	7.00
`^`	Bitwise XOR	`EVAL 5 ^ 3`	6.00
`~`	Bitwise NOT (unary)	`EVAL ~0 & 0xFF`	255.00
`sl`	Shift left	`EVAL 2 sl 1`	4.00
`sr`	Shift right	`EVAL 4 sr 1`	2.00

📝 Output Format

Customize result presentation using C printf syntax:

Format	Description	Example	Result
`%.2f`	Float 2 decimals	`EVAL 3.14159:%.2f`	3.14
`%.3f`	Float 3 decimals	`EVAL 3.14159:%.3f`	3.142
`%d`	Integer	`EVAL 5.7:%d`	5
`%x`	Lowercase hexadecimal	`EVAL 15:%x`	f
`%X`	Uppercase hexadecimal	`EVAL 15:%X`	F
`%b`	Binary	`EVAL 5:%b`	101
`%05.2f`	Left zero padding	`EVAL 3.14:%05.2f`	03.14
`%08.2f`	More left zero padding	`EVAL 3.14:%08.2f`	00003.14

⚠️ Error Handling

Custom error value


>EVAL toker + 5:%0.2f:NA<

Result: NA (undefined variable)

Default error


>EVAL toker + 5<

Result: ERR

Division by zero


>EVAL 10 / 0<

Result: Inf

💬 Practical Examples

GPS Heading (HDG)


>EVAL HDG<

Returns current heading in degrees (0-360°). Example: 185.00


>EVAL HDG ge 180<

Returns 1.00 if the vehicle points south-west-north (180°-360°).


>EVAL (HDG ge 0) && (HDG lt 90)<

Returns 1.00 if pointing north-east (0°-90°).

ECU parameter sum


>EVAL ECU(0;0) + ECU(1;0) + ECU(2;0):%0.2f<

Sums ECU values from indices 0, 1, and 2.

AIN comparison


>EVAL AIN(0) gt 500<

Returns 1.00 if AIN(0) > 500, otherwise 0.00.

Compound logic


>EVAL (V gt 150) && (AIN(0) lt 100)<

Verifies compound condition on voltage and analog input.

Calculation with format


>EVAL (10 * 5) + 3:%0.3f<

Result: 53.000

Complex expression


>EVAL ((AIN(0) * 10) + (AIN(1) * 5)) / 2:%0.2f:NA<

Calculates weighted average with custom format and NA error.

Bitwise mask


>EVAL IN(0) & 0x0F:%X<

Applies mask to digital input and displays in hexadecimal.

Bit shift


>EVAL 8 sr 2<

Result: 2.00 (8 >> 2)

Division with integer format


>EVAL 25 / 4:%d<

Result: 6 (integer division)

Temperature conversion


>EVAL (AIN(0) * 0.1) - 40:%0.1f:ERR<

Converts ADC reading to temperature with ERR error.

🔧 Error Troubleshooting

Error	Cause	Solution
`ERR`	Undefined variable or incorrect syntax	Check spelling, use `error_value`
`Inf`	Division by zero	Validate divisor or use `error_value`
Syntax	Unbalanced parentheses	Review expression structure
Index	Out of range (e.g., `AIN(9)`)	Check valid ranges for model

Compatibility

ZE-IoT

SP-IoT

SM-IoT