TwinCAT ADS controller

Contents

• TwinCAT ADS controller

  • Setup

  • EAPI methods

    • action

    • kill

    • terminate

    • var.get

    • var.set

    • var.set_bulk

Allows to communicate with Beckhoff TwinCAT ADS PLCs and other equipment.

As TwinCAT ADS does not allow to connect more than a single client from a single machine (IP), the service instances require TwinCAT ADS bridge to be deployed for each TwinCAT system.

Setup

Use the template EVA_DIR/share/svc-tpl/svc-tpl-controller-ads.yml:

# TwinCAT ADS controller gateway service
command: svc/eva-controller-ads
bus:
  path: var/bus.ipc
config:
  ads: 
    bridge_svc: eva.bridge.ads1
    ams_netid: 192.168.1.100.1.1
    #ams_port: 851
    # Allow SUMUP write and write_read requests (default: true)
    # Set false for ADS servers which unsupport this feature
    #bulk_allow: true
  # PLC ping interval, in seconds, default: timeout / 2
  #ping_interval: 1
  # panic on critical errors in X seconds after happened (0 - panic immediately)
  panic_in: 0
  # Allows the service to restart (send "stop" RPC call to) the mapped ADS
  # bridge on panic. This can be required to fix ADS connection/AMS routes in
  # certain cases
  #restart_bridge_on_panic: false
  # default retry attempts for all operations (0 - no retries, give up if the
  # first attempt fails)
  retries: 2
  # an optional delay betwen writing symbols and verifying written value
  #verify_delay: 0.1
  # event queue size, pull events ARE DROPPED on overflow. consider ALWAYS
  # having queue size > max possible symbols pulled
  queue_size: 32768
  # ttl cache for pull events (sec, skip non-modified)
  pull_cache_sec: 3600
  # PLC pull interval, in seconds
  pull_interval: 1
  # pull symbols and parse maps
  #
  #pull:
     #pull an array
    #- symbol: test_arrays.test_float_array
      #map:
        #- idx: 0 # payload index, starting from zero
        #  oid: sensor:tests/test0
        #- idx: 4
          #oid: sensor:tests/test1
          #value_delta: 0.5 # report event only if the new value difference is >=
          #transform:
            #- func: multiply # multiply the value by N
              #params: [ 1000 ]
            #- func: divide # divide the value by N
              #params: [ 1000 ]
            #- func: round # round the value to N digits after comma
              #params: [ 2 ]
            #- func: calc_speed # use the value as calc-speed gauge (with N seconds delta)
              #params: [ 1 ]
            #- func: invert # invert the value between 0/1
            # #params: []
    # pull a symbol
    #- symbol: test_arrays.test_float_array[5]
      #map:
         #- oid: sensor:tests/test2
  # action queue size, per item, actions on overflow are not dropped but wait
  # their attempt to enter the queue. The core marks an action as failed if it
  # does not enter the queue for <action timeout> seconds
  action_queue_size: 32
  # verify written data for actions
  actions_verify: true
  # OID map for actions
  #action_map:
    #unit:tests/u1:
      #symbol: test_arrays.test_float_array[0]
timeout:
  # startup timeout should be slightly langer than default to allow the
  # controller prepare connection pool and request pull/action handles
  startup: 10
user: nobody
react_to_fail: true

Create the service using eva-shell:

eva svc create eva.controller.ads1 /opt/eva4/share/svc-tpl/svc-tpl-controller-ads.yml

or using the bus CLI client:

cd /opt/eva4
cat DEPLOY.yml | ./bin/yml2mp | \
    ./sbin/bus ./var/bus.ipc rpc call eva.core svc.deploy -

(see eva.core::svc.deploy for more info)

EAPI methods

See EAPI commons for the common information about the bus, types, errors and RPC calls.

action

Description	Executes a mapped unit action
Parameters	See Unit actions
Returns	See Unit actions

kill

Description	Attempts to terinate/cancel all actions for a unit
Parameters	See Unit actions
Returns	See Unit actions

terminate

Description	Attempts to terminate/cancel a unit action
Parameters	See Unit actions
Returns	See Unit actions

var.get

Description	Get symbol from ADS
Parameters	required
Returns	Symbol value, single or list

Parameters

Name	Type	Description	Required
i	String	symbol name	yes
timeout	f64	Max operation timeout	no
retries	u8	Retry attempts	no

var.set

Description	Set symbol on ADS
Parameters	required
Returns	nothing

Parameters

Name	Type	Description	Required
i	String	symbol name	yes
value	Any	value to set	yes
verify	bool	Read the symbol back and verify its value	no
timeout	f64	Max operation timeout	no
retries	u8	Retry attempts	no

var.set_bulk

Description	Set symbols on ADS in bulk
Parameters	required
Returns	Operation status: failed-to-set symbols list or an empty dict

Parameters

Name	Type	Description	Required
i	Vec<String>	symbol names	yes
values	Vec<Any>	values to set	yes
verify	bool	Read the symbols back and verify their values	no
timeout	f64	Max operation timeout	no
retries	u8	Retry attempts	no

Return payload example:

{
  "failed": [ "var1" ]
}