Omega A2400 manual Command Response *01OC1D Single Command Module Address

Page 58

Extended Addressing 9-6

This command will close the channel at A2400 #01 and open the channel at A2400 #02. This is the quickest method of opening and closing A2400 channels. It also offers the least amount of data security. A2400 #01 was closed solely upon detecting the ‘{‘ character. There is no confirmation that A2400 #01 is closed. If A2400 #01 missed the ‘{‘ character due to noise, it would remain open, with the possibility of two A2400’s in the open condition, an undesirable state of affairs. This method has merit in systems with a known clean communications channel and when speed is important.

Another variation of the implied OC command is the long form:

Command: }01

Response: *01OC1D

Single Command Module Address

Any module located on an RS-485 string may be individually addressed with one command by appending the module command to an implied OC command:

Command: {01$1RD

Response: *+00100.00

In this command form, the {01 is an implied Open Channel command to A2400 #01. The ‘{‘ is also an implied Close Channel command to all other A2400’s. It is followed immediately by a $1RD command, which is the Read Data command for module #1 connected to A2400 #01. No response results from the {01 portion of the command, but the $1RD data is transmitted on the RS-485 bus. Module #1 responds back with the data *+00100.00.

Again, this command form is a trade-off between speed and data security. It is a convenient command form to communicate with an individual module without explicitly opening or closing an A2400 channel. This could be a good command format to be used with noise-free data channels and where speed is very important.

Explicit Open and Close Channel Commands

A greater level of data integrity may be obtained by using explicit forms of the Open Channel (OC) and Close Channel (CC) commands. This simply means that the ‘data gate’ is controlled by command sequences that require a confirmation from the addressed A2400.

Image 58
Contents User’sGuide For immediate technical or application assistance Servicing North AmericaServicing Europe BOX Revised 4/17/95Omega Engineering ONE Omega Drive STAMFORD, CT Phone 1-800-DAS-IEEETable of Contents Chapter Getting Started IntroductionSystem Overview Leased Lines$1RD +99999.99Default Mode Page Block Diagram Chapter Functional DescriptionFunctional Description Pinout A2400 Operation RS-485 TerminationCharacter Filter Page Programmable Delay Times Page Command $1RD Response *+99999.99 Chapter CommunicationsDO, OC, CC, RD, REA, RID, RLP, RS, RSP, RSU Communication RS-485 Multidrop System DATA+Page Chapter A2400 Command Set Command StructureMiscellaneous Protocol Notes Data StructureWrite Protection Response StructureCommand Checksum Long Form Responses?1 BAD Checksum ?1 Syntax Error$1WEF A2400 User Commands A2400 Command Set RT3Command $1DO01 Response Command #1DO01 Response *1DO014F Command DescriptionsCommand 01CC Response Response *01CC11 Digital Output do Closed Channel CC ExtendedCommand $1DO00 Response Command #1DO00 Response *1DO004E Extended Address EA#1ID Tank Farm $1ID Tank Farm1ID Tank Farm 1CD Open Channel OC Extended Command 01OC Response Response *01OCEDRead Data RD #1RID $1RIDTank Farm 1RID Tank Farm 11F$1RSP $1RSU#1RSU #1RSPResponse *1RT1+00100.00DC Read Time Delay 2 RT2 Read Time Delay 1 RT1Response *+00100.00 Page Page Short Prompt SP Address Error Command 01WE Response *01WE27Error Messages BAD ChecksumSyntax Error Command ErrorParity Error Value ErrorCommand Syntax Chapter Setup Information/SetUp Command$1SUbyte 1byte 2byte 3byte Byte Byte 1 Ascii Printable Characters HEX AsciiParity Baud RateCommand $1WE Response Command $1SU31020000 Command $1RS Response *31070000Command $1RS Response *31020102 Command $1WE Byte 2 Linefeed, Parity and Baud Rate Command $1RR ResponseBit BaudNormal addressing Chapter Delay Time Programming Delay Time Programming Page Command $1T3+00050.00 Set T3 to 50 ms Response Command $1RT1 Response *+00100.00Chapter Power Supply Symptom RS-232 Module is not responding to commands Chapter TroubleshootingSymptom RS-485 Module is not responding to commands Open/Close Channel Commands Command 01WE ResponseChapter Extended Addressing Typical system overview Command 01CC Response Command 01OC ResponseCommand $1RD Response +00100.00 Typical $2RD +00123.45 Command 02OC ResponseStructured Addressing Extended Address SyntaxImplied OC Command OC and CC Command FormatsImplied CC Command Command ResponseCommand 01$1RD Response *+00100.00 Command Response *01OC1D Single Command Module AddressExplicit Open and Close Channel Commands Command 01CC Response 01CC11 ‘11’ is the checksum Command 02OC Response 02OC1E ‘1E’ is the checksumChapter Transparent Mode Transparent Mode FunctionsA2400 interfacing a PLC to a leased-line modem A2400 networking several RS-232 devices to a host computer A2400 interfacing a laboratory instrument with modules Transparent Mode Adding secondary control using A2400 modules Transparent Mode WARRANTY/DISCLAIMER Shop online at omega.com