[小 迪 导读]：OPC软件作为工业自动化领域应用最广泛的软件，深受工业控制人员的喜爱。但也有许多情况下，OPC软件并不能满足实际的使用需求：
使用场景
1.OPC只在内网运行，希望可以将数据传递至外网，随时随地查看
2.OPC数据难以存库
3.希望可以更好展示数据，进行数据分析
整体交互图
1. dgiot_dtu从kepserver获取数据
在opc与kepserver完成连接之后，dgiot_dtu通过调用GetOpcDaService函数连接kepserver实现数据回调
public OpcDaService GetOpcDaService(string host, string serviceProgId)
{
var service = hostCollection.Where(a => a.ServiceIds.Contains(serviceProgId) && a.Host == host)
.FirstOrDefault();
if (service == null)
{
return null;
}
OpcDaService service1 = null;
if (CheckServiceExisted(service, serviceProgId))
{
service1 = opcDaServices.Find(item => { return item.Host == service.Host && item.ServiceId == serviceProgId; });
}
else
{
OpcDaServer daService = new OpcDaServer(serviceProgId, service.Host);
service1 = new OpcDaService()
{
Host = service.Host,
ServiceId = serviceProgId,
Service = daService,
OpcDaGroupS = new Dictionary<string, OpcDaGroup>()
};
opcDaServices.Add(service1);
}
if (service1.Service.IsConnected == false)
{
try
{
service1.Service.ConnectionStateChanged += new EventHandler<OpcDaServerConnectionStateChangedEventArgs>(ConnectionStateChanged);
service1.Service.Connect();
}
catch (Exception e)
{
LogHelper.Log("Connect " + service1.Host + ", ServiceId " + service1.ServiceId + "error!!" + e.Message);
}
}
return service1;
}
2. dgiot_dtu数据发布
dgiot_dtu在完成数据收集后，和dgiot平台连接是通过mqtt来进行连接，dgiot_dtu作为设备端进行发布、dgiot平台作为服务端进行订阅
public void ValueChangedCallBack(OpcDaGroup group, OpcDaItemValue[] values)
{
string groupKey = "";
JsonObject properties = new JsonObject();
values.ToList().ForEach(v =>
{
if (v.Item != null && v.Value != null)
{
properties.Add(v.Item.ItemId, v.Value);
groupKey = v.Item.UserData as string;
OpcDa.setItems(groupKey, v.Item.ItemId, properties);
}
});
string topic = "$dg/thing/" + productId + "/" + devAddr + "/properties/report";
MqttClientHelper.Publish(topic, Encoding.UTF8.GetBytes(properties.ToString()));
return;
}
3.平台通过dlink进行数据点位转换
在dgiot收到订阅信息时，在dink中调用on_message_publish来匹配topic类型进行点位转换
on_message_publish(Message = #message{topic = <<"$dg/thing/", Topic/binary>>, payload = Payload, from = _ClientId, headers = _Headers}, _State) ->
case re:split(Topic, <<"/">>) of
[ProductId, DevAddr, <<"properties">>, <<"report">>] ->
dgiot_dlink_proctol:properties_report(ProductId, DevAddr, get_payload(Payload));
[ProductId, DevAddr, <<"firmware">>, <<"report">>] ->
dgiot_dlink_proctol:firmware_report(ProductId, DevAddr, get_payload(Payload));
_ ->
pass
end,
{ok, Message};
4. 平台通过task将数据存入TD,并使用mqtt上报给物模型
完成点位转换之后，将数据存入TD数据库、同时也将数据上报给物模型展示
save_td(ProductId, DevAddr, Ack, AppData) ->
case length(maps:to_list(Ack)) of
0 ->
#{};
_ ->
NewAck = dgiot_task:get_collection(ProductId, [], Ack, Ack),
NewData = dgiot_task:get_calculated(ProductId, NewAck),
Keys = dgiot_product:get_keys(ProductId),
DeviceId = dgiot_parse_id:get_deviceid(ProductId, DevAddr),
Interval = maps:get(<<"interval">>, AppData, 3),
AllData = merge_cache_data(DeviceId, NewData, Interval),
AllDataKey = maps:keys(AllData),
case Keys -- AllDataKey of
List when length(List) == 0 andalso length(AllDataKey) =/= 0 ->
ChannelId = dgiot_parse_id:get_channelid(dgiot_utils:to_binary(?BRIDGE_CHL), <<"DGIOTTOPO">>, <<"TOPO组态通道"/utf8>>),
dgiot_channelx:do_message(ChannelId, {topo_thing, ProductId, DeviceId, AllData}),
dgiot_tdengine_adapter:save(ProductId, DevAddr, AllData),
Channel = dgiot_product:get_taskchannel(ProductId),
dgiot_bridge:send_log(Channel, ProductId, DevAddr, "~s ~p save td => ProductId ~p DevAddr ~p ~ts ", [?FILE, ?LINE, ProductId, DevAddr, unicode:characters_to_list(jsx:encode(AllData))]),
dgiot_metrics:inc(dgiot_task, <<"task_save">>, 1),
NotificationTopic = <<"$dg/user/alarm/", ProductId/binary, "/", DeviceId/binary, "/properties/report">>,
dgiot_mqtt:publish(DeviceId, NotificationTopic, jsx:encode(AllData)),
AllData;
_ ->
save_cache_data(DeviceId, AllData),
AllData
end
end.
5.平台配置物模型并数据展示
[小 迪 点评]
- 鉴此,dgiot专门提供了基于OPC通讯的OPC接口，以实现OPC数据的简单传输，解决行业痛点。
想了解更多 dgiot 的具体细节，欢迎大家在GitHub上查看相关源代码。