PTZ Control Deep Dive: RS485 Bus sariyakolow, protocoles ani gɛlɛyaw ɲɛnabɔcogo caman

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Awirilikalo tile 18, san 2023

RS485 ye diferential serial communication standard ye min bɛ baara kɛ ni taamasiyɛn sira fila ye (a bɛ fɔ cogo min na ko A ni B, walima + ani -) walasa ka kunnafoniw ci. Diferential signaling nafa jɔnjɔn ye anti-interference se barikama ye.

RS485 Farikolo Layɛrɛ: A tɛ Fila Fila Dama ye

RS485 ye diferential serial communication standard ye min bɛ baara kɛ ni taamasiyɛn sira fila ye (a bɛ fɔ cogo min na ko A ni B, walima + ani -) walasa ka kunnafoniw ci. Diferential signaling (diferential signaling) nafa jɔnjɔn ye anti-interference (dafalen-falen-falen) seko barikama ye — a sɔrɔbaga bɛ voltage danfara dɔn layini fila ninnu cɛ sanni ka voltage absolute (kurunba dafalen) kɔlɔsi ni a bɛ tali kɛ dugukolo la. O kɔrɔ ye ko mankan min bɛ kɛ cogo kelen na (i n’a fɔ fɛn min bɛ don a la ni motɛriw ye minnu bɛ kɛrɛfɛ walima minnu bɛ se ka fɛn caman sɛgɛsɛgɛ) bɛ ban a yɛrɛma.

Nka nafa min bɛ diferential signaling la, o bɛ na ni musaka ye. RS485 bisi bɛ termination resistors (a ka c’a la 120 ohms) ɲumanw de wajibiya minnu bɛ sigi bus dakun fila bɛɛ la walasa ka signal reflections ban. Ni termination resistor tununna walima ni a bilalen don yɔrɔ jugu la, signal reflections bɛ data filiw lase — a bɛ jira iko signal overshoot ani ka mankan kɛ oscilloscope kan. Ɛntɛrinɛti waleyali la, termination resistor tununen ye PTZ control dɛsɛ sababu dɔ ye min ka teli ka kɛ.

Pelco-D vs Pelco-P: Protocole sugandili tɛ kɛ ni yɛrɛmahɔrɔnya ye

PTZ kɔlɔsili fɛɛrɛ minnu bɛ kɛ ka caya lakana kɔlɔsili la, olu ye Pelco-D ani Pelco-P ye. U fila bɛɛ ye kumaɲɔgɔnya kɛcogo ye min bɛ tali kɛ ɲɔgɔn na, nka kunnafonidilanw cogoya tɛ kelen ye: Pelco-D bɛ baara kɛ ni bayt 7 cogoya ye, ka sɔrɔ Pelco-P bɛ baara kɛ ni cogoya ye min ka dɔgɔ kosɛbɛ. Protocole fila ninnu tɛ bɛn ɲɔgɔn ma — ni kamera bɛ Pelco-D dɛmɛ ani ni ɛntɛrinɛti baarakɛminɛn ye Pelco-P cikanw ci, PTZ tɛna jaabi di.

Min ka gɛlɛn ka tɛmɛ o kan, o ye ko marka suguya wɛrɛw ka protocole kelen waleyali bɛ se ka kɛ ni danfara misɛnninw ye. Misali la, marka dɔw ka Pelco-D waleyali la, PTZ teliya kodeli tɛ kelen ye ni sariya ye, o bɛ na ni kunnafoniko tiɲɛni dɔgɔyali ye. Porozɛ minnu bɛ kɛ ni fɛn suguya ɲagaminenw ye, a ka ɲi ka protocole compatibilité sɛgɛsɛgɛ marka ni brand, sanni k’a miiri ko ‘n’u bɛɛ bɛ Pelco-D dɛmɛ, u bɛ bɛn.’ FangService ka PK69 ni PK68 seriyali bɛ Pelco-D ni Pelco-P protocol fila bɛɛ dɛmɛ, wa u bɛ se ka fɛn caman wuli u yɛrɛma walima bolo la ka da kamera taamasiyɛn kan.

Dɛsɛ minnu bɛ kɛ tuma caman na ani gɛlɛyaw ɲɛnabɔcogo

PTZ kunkanko dɛsɛ gɛlɛyaw ɲɛnabɔli bɛ taabolo sigilen de wajibiya. Gɛlɛya ɲɛnabɔcogo min bɛ fɔ, o ye : 1 farikolo lamini sɛgɛsɛgɛli (ni RS485 kabɔri ma tiɲɛ, ni A/B wiring bɛ tiɲɛ, ni termination resistor sigilen don) 2 protocol layer check (ni protocol suguya bɛ bɛn, ni baud rate bɛ bɛn, ni ladɛrɛsi code bɛ tiɲɛ); 3 minɛnw layini sɛgɛsɛgɛli (ni PTZ yɛrɛ tiɲɛna, ni kuran bɛ se, ni masin yɔrɔ sirilen don). Farikolo-yɔrɔ dɛsɛw de ka ca kosɛbɛ — A/B layini kɔsegin ye gɛlɛya ye min ka jugu kosɛbɛ bawo a ka c’a la, PTZ bɛ wuli hali bi, a bɛ taa sira wɛrɛ fɛ dɔrɔn. Debugging waati la, n’i y’a ye ko PTZ ‘bɛ kinin fɛ’ k’a sɔrɔ a ka kan ka ‘yɛrɛ kinin fɛ’, fɔlɔ ka A/B wiring lajɛ. Ko wɛrɛ min bɛ kɛ tuma caman na, o ye RS485 layini multiplexing ye ni idle wire pairs ye network cable kɔnɔ — ni wire pairs minnu bɛ kɛ RS485 ka cable kɔnɔ, olu ka twist rates tɛ bɛn data pairs ma, signal interference bɛ se ka sɔrɔ o la. FangService ka PK69 seriyali kɔnɔ, RS485 kabali sɛgɛsɛgɛli baarakɛcogo dɔ bɛ a kɔnɔ min bɛ se ka kabali tɛmɛsira, surunyali, ani crossoverw dɔn. Ni a ni protocol analyse baarakɛcogo farala ɲɔgɔn kan, a bɛ se ka dɛsɛyɔrɔ sɔrɔ joona.

RS485 Réseau Topologie ani yɔrɔjan dantigɛliw

RS485 bisi topidiya ni yɔrɔjan dantigɛliw ye gɛlɛyaw ye minnu bɛ ye nɔgɔya la ɛntɛrinɛti dilanni na. RS485 sariya bɛ bus suguya topidiya laadi — minɛnw bɛɛ bɛ ɲɔgɔn ta layiniba kelen kan, ni termination resistor bɛ layiniba laban kelen-kelen bɛɛ la. Dolow topidiya (minɛn bɛɛ minnu sirilen bɛ u yɛrɛma cɛmancɛ yɔrɔ dɔ la) bɛ kɛ sababu ye ka taamasiyɛnw jirali kɛ, o bɛ se ka kɛ sababu ye ka kumaɲɔgɔnya tiɲɛ hali ni yɔrɔjan surunw ye.

RS485 ka kumaɲɔgɔnya yɔrɔjanba bɛ bɛn baud hakɛ ma. Ni baud hakɛ dɔgɔman ye 9600bps ye, yɔrɔjanba bɛ se ka se mɛtɛrɛ 1200 ma; ni baud hakɛ cayalenba ye 115200bps ye, a ka c’a la, yɔrɔjan min ka bon kosɛbɛ, o tɛ tɛmɛ mɛtɛrɛ 200 kan. Ni PTZ minɛn minnu bɛ porozɛ dɔ kɔnɔ, olu tilalen don yɔrɔ janw na, aw bɛ a lajɛ ka seginkannifɛnw fara u kan walima ka baud hakɛ dɔgɔya. FangService ka PK69 ni PK68 seriyali, RS485 sɛgɛsɛgɛli cogo la, o bɛ se ka sisan kumaɲɔgɔnya paramɛtiriw jira (baud rate, data bits, stop bits, parity), o bɛ ɛntɛrinɛti injiniyɛriw dɛmɛ u k’a sɛgɛsɛgɛ joona ko a labɛncogo bɛnnen don.

K’a ta RS485 la ka se IP PTZ Control ma: Kumaɲɔgɔnya fɛɛrɛbɔ yiriwali

Laadalata PTZ kɔlɔsili bɛ waleya RS485 seriyali bisi fɛ, nka ikomi IP kameraw bɛ ka caya, PTZ kɔlɔsili bɛ ka wuli ka taa IP rezow siratigɛ la. Bi IP PTZ bɛ se ka kunnafonidi cikanw sɔrɔ k’a ɲɛsin ɛntɛrinɛti kabɔri ma ONVIF protocol walima feerekɛla ka protocoles fɛ, o bɛ RS485 kabɔri yɛrɛmahɔrɔnyalenw mago bɔ.

Nka RS485 tɛna tunun yanni dɔɔnin cɛ. HD sitɛmu coaxial (AHD/TVI/CVI) kɔnɔ, PTZ kɔlɔsili bɛ da RS485 kan hali bi; laadala sigida caman na minnu sigilen don kaban, RS485 dɔrɔn de ye kɔrɔsili fɛɛrɛ ye. O la, hali IP waati la, RS485 PTZ kɔlɔsili bɛ to seko nafama ye lakana injiniyɛriw bolo. FangService ka rezo sɛgɛsɛgɛli minɛnw sira bɛ RS485 PTZ kunkanko sɛgɛsɛgɛli (PK68/PK69 seriyali) ani IP rezo sɛgɛsɛgɛli (PK69 seriyali) fila bɛɛ lajɛlen kan, o bɛ sɛgɛsɛgɛli fura dafalenw di laadala ni bi sigida fila bɛɛ ma. Porozɛ ɲagaminenw kama minnu bɛ sigida kura ni sigida kɔrɔw bɛɛ lajɛlen na, nin seko fila-fila in nafa ka bon kɛrɛnkɛrɛnnenya la. View the Network Test Instruments Collection