1. Introducción
MB2HAL es un componente HAL en tiempo no-real genérico para comunicarse con uno o más dispositivos Modbus. Hasta ahora, hay dos opciones para comunicarse con un dispositivo Modbus:
-
Una opción es crear un componente HAL como un controlador, ver VFD Modbus.
-
Otra opción es usar Classic Ladder, el cual tiene Modbus interconstruido, ver ClassicLadder.
-
Ahora hay una tercera opción que consiste en un controlador "genérico" configurado por archivo de texto, y es llamada MB2HAL.
¿Por qué MB2HAL? Considera usar MB2HAL si:
-
Tienes que escribir un controlador nuevo y no sabes nada de programación.
-
Necesitas usar Classic Ladder "solo" para manejar las conexiones de Modbus.
-
Debes encontrar y configurar las transacciones Modbus por primera vez. MB2HAL tiene niveles de depuración que facilitan la depuración de protocolo de bajo nivel.
-
Tienes que conectar más de un dispositivo. MB2HAL es muy eficiente administrando múltiples dispositivos, transacciones y enlaces. Actualmente monitoreo dos controladores de ejes usando un puerto Rs232, un controlador VFD usando otro puerto Rs232 y una E/S remota usando TCP/IP.
-
Quieres un protocolo para conectar tu Arduino con HAL. Ver el archivo de ejemplo de configuración incluido, diagrama y librería para Arduino en Modbus.
2. Safety Considerations
Modbus (RTU or TCP) is not suitable as the only run-enable path for a spindle or drive. A Modbus slave such as a VFD holds the last value written to its control registers indefinitely. If LinuxCNC exits, crashes, or the serial link drops while the spindle is running, no stop command is ever sent and the spindle keeps running. MB2HAL is a non-realtime userspace component and performs no cleanup on exit, so this applies even to a clean shutdown. Writing a stop command from shutdown.hal only covers the clean-exit case and is not a safety measure.
The standard practice is to layer the control:
-
Wire the enable in hardware. The VFD enable or STO (Safe Torque Off) inputs belong in the machine estop chain, independent of any communication bus. This is the only layer that qualifies as safety. Many VFDs offer dual redundant estop inputs for use with safety relays. With this layer in place, run and stop over Modbus is accepted practice; the remaining layers decide what happens when the communication fails.
-
Arrange a stop on communication loss. Most VFDs provide a Modbus timeout parameter with a fault or coast-to-stop action; set it to a few hundred milliseconds, so a crash or dropped link stops polling and the VFD stops the motor. Alternatively detect the loss in HAL: the
mb2hal.__m__.num_errorspin counts failed transactions (0 means the last transaction succeeded), and feeding it into a machine-off or estop chain stops the machine when the link dies. HAL-side detection avoids VFD-specific parameterization and needs no rework when the VFD is replaced, but coverage of a PC crash then rests on the output hardware watchdog, for example the Mesa hostmot2 watchdog or a parallel-port charge pump. -
Optionally split the command sources. Configure run command from terminals and frequency reference from Modbus, drive the VFD run terminal from
motion.spindle-onormotion.machine-is-onthrough a relay or digital output, and let Modbus carry only speed reference, direction and status. This also avoids the read-modify-write problem when a single control register multiplexes run, stop and other commands.
These considerations apply to every Modbus control path (MB2HAL, hm2_modbus, ClassicLadder or a custom driver), not only to MB2HAL.
3. Utilización
-
Crear un archivo de configuración del ejemplo de abajo
-
Asignar el nombre del componente (opcional)
Asignar
HAL_MODULE_NAME=mimodulo(predeterminadoHAL_MODULE_NAME=mb2hal) -
Carga el componente HAL de tiempo no-real modbus
-
-
Nombre de componente predeterminado:
loadusr -W mb2hal config=config_file.ini -
Nombre de componente personalizado:
loadusr -Wn mimodulo mb2hal config=config_file.ini
4. Opciones
4.1. Sección Init
[MB2HAL_INIT]
| Valor | Tipo | Requerido | Descripción |
|---|---|---|---|
|
Entero |
No |
Nivel de depuración de init y parseo del archivo INI. |
|
Cadena |
No |
Número de versión en el formato N.N[NN]. Predeterminado a 1.0. |
|
Cadena |
No |
Nombre del módulo (componente) HAL. Predeterminado a "mb2hal". |
|
Flotante |
No |
Inserta un retardo de "FLOTANTE segundos" entre
transacciones con el fin de no tener mucho que registrar y facilitar la depuración.
Útil cuando se usa |
|
Entero |
Sí |
El número total de transacciones Modbus. No hay máximo. |
4.2. Secciones de transacción
Se requiere una sección de transacción por transacción, comenzando con [TRANSACTION_00] y contando hacia arriba secuencialmente. Si hay un enlace nuevo (sin transacción) debes proporcionar los parámetros REQUERIDOS la 1era vez. Advertencia: Cualquier parámetro OPCIONAL no especificado es copiado de la transacción previa.
| Valor | Tipo | Requerido | Descripción |
|---|---|---|---|
|
Cadena |
Sí |
Debes especificar un enlace "serial" o "tcp" para la primera transacción. Transacciones posteriores usarán el enlace de la transacción anterior si no se especifica. |
|
Dirección IP |
Si |
La dirección IP del dispositivo Modbus esclavo. Ignorada si |
|
Entero |
No |
El puerto del dispositivo Modbus esclavo. Predeterminado a 502. Ignorado si |
|
Cadena |
Si |
El puerto serie. Por ejemplo "/dev/ttyS0". Ignorado si |
|
Entero |
Si |
La velocidad en baudios. Ignorado si |
|
Entero |
Si |
Bits de datos. Uno de 5, 6, 7 u 8. Ignorado si |
|
Cadena |
Si |
Paridad de datos. Uno de: even, odd o none. Ignorado si |
|
Entero |
Si |
Bits de parada. Uno de 1, 2. Ignorado si |
|
Entero |
Si |
Retardo de puerto serial entre transacciones de solo esta sección. En ms. Predeterminado a 0. Ignorado si |
|
Entero |
Sí |
Número de esclavo Modbus. |
|
Entero |
Sí |
La dirección del primer elemento. |
|
Entero |
A menos que se especifique |
El número de elementos.
Es un error especificar ambos |
|
Lista |
A menos que `NELEMENTS`este especificado |
Una lista de nombres de elementos. Estos nombres se usarán para los nombres de pines, p. ej. mb2hal.plcin.cycle_start. |
|
Cadena |
Sí |
Código de la función de transacción de Modbus (ver especificaciones): • fnct_01_read_coils |
|
Entero |
No |
Tiempo de expiración de respuesta para esta transacción. En ms. Predeterminado a 500 ms. Esto es cuánto esperar al 1er byte antes de mandar un error. |
|
Entero |
No |
Tiempo de expiración de byte para esta transacción. En ms. Predeterminado a 500 ms. Esto es cuánto esperar de un byte a otro antes de mandar un error. |
|
Cadena |
No |
En lugar de dar un número de transacción usar un nombre. Ejemplo: |
|
Flotante |
No |
Velocidad máxima de actualización en Hz. Predeterminado a 0.0 (0.0 = en cuanto este disponible = infinito).
NOTA: Esta es la tasa máxima y la tasa real puede ser menor. Si se quiere calcular en ms usar (1000 / ms_requeridos).
Ejemplo: 100 ms = |
|
Cadena |
No |
Nivel de depuración para solo esta transacción. Ver el parámetro |
4.3. Códigos de error
Al depurar transacciones nota que el valor devuelto "ret[]" corresponde a:
Excepciones de protocolo Modbus:
-
0x01 - ILLEGAL_FUNCTION - the FUNCTION code received in the query is not allowed or invalid.
-
0x02 - ILLEGAL_DATA_ADDRESS - the DATA ADDRESS received in the query is not an allowable address for the slave or is invalid.
-
0x03 - ILLEGAL_DATA_VALUE - a VALUE contained in the data query field is not an allowable value or is invalid.
-
0x04 - SLAVE_DEVICE_FAILURE - SLAVE (or MASTER) device unrecoverable FAILURE while attempting to perform the requested action.
-
0x04 - SERVER_FAILURE - (see above).
-
0x05 - ACKNOWLEDGE - This response is returned to PREVENT A TIMEOUT in the master. A long duration of time is required to process the request in the slave.
-
0x06 - SLAVE_DEVICE_BUSY - The slave (or server) is BUSY. Retransmit the request later.
-
0x06 - SERVER_BUSY - (see above).
-
0x07 - NEGATIVE_ACKNOWLEDGE - Unsuccessful programming request using function code 13 or 14.
-
0x08 - MEMORY_PARITY_ERROR - SLAVE parity error in MEMORY.
-
0x0A (-10) - GATEWAY_PROBLEM_PATH - Gateway path(s) not available.
-
0x0B (-11) - GATEWAY_PROBLEM_TARGET - The target device failed to respond (generated by master, not slave).
Programa o conexión:
-
0x0C (-12) - COMM_TIME_OUT
-
0x0D (-13) - PORT_SOCKET_FAILURE
-
0x0E (-14) - SELECT_FAILURE
-
0x0F (-15) - TOO_MANY_DATAS
-
0x10 (-16) - INVALID_CRC
-
0x11 (-17) - INVALID_EXCEPTION_CODE
5. Archivo de configuración de ejemplo
Clic aquí para descargar.
#This .INI file is also the HELP, MANUAL and HOW-TO file for mb2hal.
#Load the Modbus HAL userspace module as the examples below,
#change to match your own HAL_MODULE_NAME and INI file name
#Using HAL_MODULE_NAME=mb2hal or nothing (default): loadusr -W mb2hal config=config_file.ini
#Using HAL_MODULE_NAME=mymodule: loadusr -Wn mymodule mb2hal config=config_file.ini
# ++++++++++++++++++++++++
# Common section
# ++++++++++++++++++++++++
[MB2HAL_INIT]
#OPTIONAL: Debug level of init and INI file parsing.
# 0 = silent.
# 1 = error messages (default).
# 2 = OK confirmation messages.
# 3 = debugging messages.
# 4 = maximum debugging messages (only in transactions).
INIT_DEBUG=3
#OPTIONAL: Set to 1.1 to enable the new functions:
# - fnct_01_read_coils
# - fnct_05_write_single_coil
# - changed pin names (see https://linuxcnc.org/docs/2.9/html/drivers/mb2hal.html#_pins).
VERSION=1.1
#OPTIONAL: HAL module (component) name. Defaults to "mb2hal".
HAL_MODULE_NAME=mb2hal
#OPTIONAL: Insert a delay of "FLOAT seconds" between transactions in order
#to not to have a lot of logging and facilitate the debugging.
#Useful when using DEBUG=3 (NOT INIT_DEBUG=3)
#It affects ALL transactions.
#Use "0.0" for normal activity.
SLOWDOWN=0.0
#REQUIRED: The number of total Modbus transactions. There is no maximum.
TOTAL_TRANSACTIONS=9
# ++++++++++++++++++++++++
# Transactions
# ++++++++++++++++++++++++
#One transaction section is required per transaction, starting at 00 and counting up sequentially.
#If there is a new link (not transaction), you must provide the REQUIRED parameters 1st time.
#Warning: Any OPTIONAL parameter not specified are copied from the previous transaction.
[TRANSACTION_00]
#REQUIRED: You must specify either a "serial" or "tcp" link for the first transaction.
#Later transaction will use the previous transaction link if not specified.
LINK_TYPE=tcp
#if LINK_TYPE=tcp then REQUIRED (only 1st time): The Modbus slave device ip address.
#if LINK_TYPE=serial then IGNORED
TCP_IP=192.168.2.10
#if LINK_TYPE=tcp then OPTIONAL.
#if LINK_TYPE=serial then IGNORED
#The Modbus slave device tcp port. Defaults to 502.
TCP_PORT=502
#if LINK_TYPE=serial then REQUIRED (only 1st time).
#if LINK_TYPE=tcp then IGNORED
#The serial port.
SERIAL_PORT=/dev/ttyS0
#if LINK_TYPE=serial then REQUIRED (only 1st time).
#if LINK_TYPE=tcp then IGNORED
#The baud rate.
SERIAL_BAUD=115200
#if LINK_TYPE=serial then REQUIRED (only 1st time).
#if LINK_TYPE=tcp then IGNORED
#Data bits. One of 5,6,7,8.
SERIAL_BITS=8
#if LINK_TYPE=serial then REQUIRED (only 1st time).
#if LINK_TYPE=tcp then IGNORED
#Data parity. One of: even, odd, none.
SERIAL_PARITY=none
#if LINK_TYPE=serial then REQUIRED (only 1st time).
#if LINK_TYPE=tcp then IGNORED
#Stop bits. One of 1, 2.
SERIAL_STOP=2
#if LINK_TYPE=serial then OPTIONAL:
#if LINK_TYPE=tcp then IGNORED
#Serial port delay between for this transaction only.
#In ms. Defaults to 0.
SERIAL_DELAY_MS=10
#REQUIRED (only 1st time).
#Modbus slave number.
MB_SLAVE_ID=1
#REQUIRED: The first element address (decimal integer).
FIRST_ELEMENT=0
#REQUIRED unless PIN_NAMES is specified: The number of elements.
#It is an error to specify both NELEMENTS and PIN_NAMES
#The pin names will be sequential numbers e.g mb2hal.plcin.01
#NELEMENTS=4
#REQUIRED unless NELEMENTS is specified: A list of element names.
#these names will be used for the pin names, e.g mb2hal.plcin.cycle_start
#NOTE: there must be no white space characters in the list
PIN_NAMES=cycle_start,stop,feed_hold
#REQUIRED: Modbus transaction function code (see www.modbus.org specifications).
# fnct_01_read_coils (01 = 0x01) (new in 1.1)
# fnct_02_read_discrete_inputs (02 = 0x02)
# fnct_03_read_holding_registers (03 = 0x03)
# fnct_04_read_input_registers (04 = 0x04)
# fnct_05_write_single_coil (05 = 0x05) (new in 1.1)
# fnct_06_write_single_register (06 = 0x06)
# fnct_15_write_multiple_coils (15 = 0x0F)
# fnct_16_write_multiple_registers (16 = 0x10)
#
# Created pins:
# fnct_01_read_coils:
# fnct_02_read_discrete_inputs:
# mb2hal.m.n.bit (output)
# mb2hal.m.n.bit-inv (output)
# fnct_03_read_holding_registers:
# fnct_04_read_input_registers:
# mb2hal.m.n.float (output)
# mb2hal.m.n.int (output)
# fnct_05_write_single_coil:
# mb2hal.m.n.bit (input)
# NELEMENTS needs to be 1 or PIN_NAMES must contain just one name.
# fnct_06_write_single_register:
# mb2hal.m.n.float (input)
# mb2hal.m.n.int (input)
# NELEMENTS needs to be 1 or PIN_NAMES must contain just one name.
# Both pin values are added and limited to 65535 (UINT16_MAX). Normally use one and let the other open (read as 0).
# fnct_15_write_multiple_coils:
# mb2hal.m.n.bit (input)
# fnct_16_write_multiple_registers:
# mb2hal.m.n.float (input)
# mb2hal.m.n.int (input)
# Both pin values are added and limited to 65535 (UINT16_MAX). Normally use one and let the other open (read as 0).
#
# m = HAL_TX_NAME or transaction number if not set, n = element number (NELEMENTS) or name from PIN_NAMES
# Example: mb2hal.00.01.<type> (transaction=00, second register=01 (00 is the first one))
# mb2hal.TxName.01.<type> (HAL_TX_NAME=TxName, second register=01 (00 is the first one))
MB_TX_CODE=fnct_03_read_holding_registers
#OPTIONAL: Response timeout for this transaction. In INTEGER ms. Defaults to 500 ms.
#This is how much to wait for 1st byte before raise an error.
MB_RESPONSE_TIMEOUT_MS=500
#OPTIONAL: Byte timeout for this transaction. In INTEGER ms. Defaults to 500 ms.
#This is how much to wait from byte to byte before raise an error.
MB_BYTE_TIMEOUT_MS=500
#OPTIONAL: Instead of giving the transaction number, use a name.
#Example: mb2hal.00.01 could become mb2hal.plcin.01
#The name must not exceed 28 characters.
#NOTE: when using names be careful that you dont end up with two transactions
#using the same name.
HAL_TX_NAME=remoteIOcfg
#OPTIONAL: Maximum update rate in HZ. Defaults to 0.0 (0.0 = as soon as available = infinite).
#NOTE: This is a maximum rate and the actual rate may be lower.
#If you want to calculate it in ms use (1000 / required_ms).
#Example: 100 ms = MAX_UPDATE_RATE=10.0, because 1000.0 ms / 100.0 ms = 10.0 Hz
MAX_UPDATE_RATE=0.0
#OPTIONAL: Debug level for this transaction only.
#See INIT_DEBUG parameter above.
DEBUG=2
#While DEBUGGING transactions note the returned "ret[]" value correspond to:
#/* Modbus protocol exceptions */
#ILLEGAL_FUNCTION -0x01 the FUNCTION code received in the query is not allowed or invalid.
#ILLEGAL_DATA_ADDRESS -0x02 the DATA ADDRESS received in the query is not an allowable address for the slave or is invalid.
#ILLEGAL_DATA_VALUE -0x03 a VALUE contained in the data query field is not an allowable value or is invalid.
#SLAVE_DEVICE_FAILURE -0x04 SLAVE (or MASTER) device unrecoverable FAILURE while attempting to perform the requested action.
#SERVER_FAILURE -0x04 (see above).
#ACKNOWLEDGE -0x05 This response is returned to PREVENT A TIMEOUT in the master.
# A long duration of time is required to process the request in the slave.
#SLAVE_DEVICE_BUSY -0x06 The slave (or server) is BUSY. Retrasmit the request later.
#SERVER_BUSY -0x06 (see above).
#NEGATIVE_ACKNOWLEDGE -0x07 Unsuccessful programming request using function code 13 or 14.
#MEMORY_PARITY_ERROR -0x08 SLAVE parity error in MEMORY.
#GATEWAY_PROBLEM_PATH -0x0A (-10) Gateway path(s) not available.
#GATEWAY_PROBLEM_TARGET -0x0B (-11) The target device failed to respond (generated by master, not slave).
#/* Program or connection */
#COMM_TIME_OUT -0x0C (-12)
#PORT_SOCKET_FAILURE -0x0D (-13)
#SELECT_FAILURE -0x0E (-14)
#TOO_MANY_DATAS -0x0F (-15)
#INVALID_CRC -0x10 (-16)
#INVALID_EXCEPTION_CODE -0x11 (-17)
[TRANSACTION_01]
MB_TX_CODE=fnct_01_read_coils
FIRST_ELEMENT=1024
NELEMENTS=24
HAL_TX_NAME=remoteIOin
MAX_UPDATE_RATE=0.0
DEBUG=1
[TRANSACTION_02]
MB_TX_CODE=fnct_02_read_discrete_inputs
FIRST_ELEMENT=1280
NELEMENTS=8
HAL_TX_NAME=readStatus
MAX_UPDATE_RATE=0.0
[TRANSACTION_03]
MB_TX_CODE=fnct_05_write_single_coil
FIRST_ELEMENT=100
NELEMENTS=1
HAL_TX_NAME=setEnableout
MAX_UPDATE_RATE=0.0
[TRANSACTION_04]
MB_TX_CODE=fnct_15_write_multiple_coils
FIRST_ELEMENT=150
NELEMENTS=10
HAL_TX_NAME=remoteIOout
MAX_UPDATE_RATE=0.0
[TRANSACTION_05]
LINK_TYPE=serial
SERIAL_PORT=/dev/ttyS0
SERIAL_BAUD=115200
SERIAL_BITS=8
SERIAL_PARITY=none
SERIAL_STOP=2
SERIAL_DELAY_MS=50
MB_SLAVE_ID=1
MB_TX_CODE=fnct_03_read_holding_registers
FIRST_ELEMENT=1
NELEMENTS=2
HAL_TX_NAME=XDrive01
MAX_UPDATE_RATE=0.0
DEBUG=1
[TRANSACTION_06]
MB_TX_CODE=fnct_04_read_input_registers
FIRST_ELEMENT=12
NELEMENTS=3
HAL_TX_NAME=XDrive02
MAX_UPDATE_RATE=10.0
DEBUG=1
[TRANSACTION_07]
MB_TX_CODE=fnct_06_write_single_register
FIRST_ELEMENT=20
NELEMENTS=1
HAL_TX_NAME=XDrive03
MAX_UPDATE_RATE=0.0
DEBUG=1
[TRANSACTION_08]
MB_TX_CODE=fnct_16_write_multiple_registers
FIRST_ELEMENT=55
NELEMENTS=8
HAL_TX_NAME=XDrive04
MAX_UPDATE_RATE=10.0
DEBUG=1
6. Pines
|
Note
|
Yellow = Nuevo en MB2HAL 1.1 (LinuxCNC 2.9) Para usar estas nuevas características debes asignar m = Valor de Ejemplo:
|
6.1. fnct_01_read_coils
-
mb2hal.m.n.bit bit out
-
mb2hal.m.n.bit-inv bit out
6.2. fnct_02_read_discrete_inputs
-
mb2hal.m.n.bit bit out
-
mb2hal.m.n.bit-inv bit out
6.3. fnct_03_read_holding_registers
-
mb2hal.m.n.float float out
-
mb2hal.m.n.int s32 out
6.4. fnct_04_read_input_registers
-
mb2hal.m.n.float float out
-
mb2hal.m.n.int s32 out
6.5. fnct_05_write_single_coil
-
mb2hal.m.n.bit bit in
NELEMENTS necesita ser 1 o PIN_NAMES debe contener solo un nombre.
6.6. fnct_06_write_single_register
-
mb2hal.m.n.float float in
-
mb2hal.m.n.int s32 in
NELEMENTS necesita ser 1 o PIN_NAMES debe contener solo un nombre. Ambos valores de pines están sumados y limitados a 65535 (UINT16_MAX). Usar uno y dejar el otro abierto (leer como 0).
6.7. fnct_15_write_multiple_coils
-
mb2hal.m.n.bit bit in
6.8. fnct_16_write_multiple_registers
-
mb2hal.m.n.float float in
-
mb2hal.m.n.int s32 in
Ambos valores de pines son sumados y limitados a 65535 (UINT16_MAX). Usar uno y dejar el otro abierto (leer como 0).