Omega A2400 manual Byte

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SetUp Command 5-2

A typical SetUp command would look like: $1SU31070102

Notice that each byte is represented by its two-character ASCII equivalent. In this example, byte 1 is described by the ASCII characters ‘31’ which is the equivalent of binary 0011 0001 (31 hex). The operand of a SU command must contain exactly 8 hex (0-F) characters. Any deviation from this format will result in a SYNTAX ERROR.

For the purposes of describing the SetUp command, ‘bit 7’ refers to the highest-order bit of a byte of data. ‘Bit 0’ refers to lowest-order bit

‘bit number’:

7

6

5

4

3

2

1

0

 

binary data:

0

0

1

1

0

0

0

1

= $31 (hex)

The SU command is write protected to guard against erroneous changes in the setup data; therefore each SU command must be preceded by a Write Enable (WE) command. To abort an SU command in progress, simply send a non-hex character (an ‘X’ for example) to generate a SYNTAX ERROR, and try again.

Caution: Care must be exercised in using the SU command. Improper use may result in changing communications parameters (address, baud rate, parity) which will result in a loss of communications between the host and the module. In some cases the user may have to resort to using Default Mode to restore the proper setups. The recommended procedure is to first use the Read Setup (RS) command to examine the existing setup data before proceeding with the SU command.

Byte 1

Byte 1 contains the A2400 address. The address is stored as the ASCII code for the string character used to address the module. In our example command $1SU31070102 , the first byte ‘31’ is the ASCII code for the character ‘1’. If our sample command is sent to a module, the EEPROM will be loaded with the address ‘1’, which in this particular case remains unchanged. To change the module address to ‘2’ , byte 1 of the SetUp command becomes ‘32’, which is the ASCII code for the character ‘2’. Now the command will look like this: $1SU32070102. When this command is sent, the module address is changed from ‘1’ to ‘2’.

The module will no longer respond to address ‘1’.

When using the SU command to change the address of a module, be sure to record the new address in a place that is easily retrievable. The only way

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Contents User’sGuide Servicing Europe Servicing North AmericaFor immediate technical or application assistance Omega Engineering ONE Omega Drive Revised 4/17/95BOX STAMFORD, CT Phone 1-800-DAS-IEEETable of Contents Introduction Chapter Getting StartedLeased Lines System Overview+99999.99 $1RDDefault Mode Page Chapter Functional Description Block DiagramFunctional Description Pinout Character Filter RS-485 TerminationA2400 Operation Page Programmable Delay Times Page Chapter Communications Command $1RD Response *+99999.99DO, OC, CC, RD, REA, RID, RLP, RS, RSP, RSU Communication DATA+ RS-485 Multidrop SystemPage Command Structure Chapter A2400 Command SetWrite Protection Data StructureMiscellaneous Protocol Notes Response StructureLong Form Responses Command Checksum$1WEF ?1 Syntax Error?1 BAD Checksum A2400 User Commands RT3 A2400 Command SetCommand 01CC Response Response *01CC11 Digital Output do Command DescriptionsCommand $1DO01 Response Command #1DO01 Response *1DO014F Closed Channel CC ExtendedExtended Address EA Command $1DO00 Response Command #1DO00 Response *1DO004E1ID Tank Farm 1CD $1ID Tank Farm#1ID Tank Farm Read Data RD Command 01OC Response Response *01OCEDOpen Channel OC Extended Tank Farm $1RID#1RID 1RID Tank Farm 11F#1RSU $1RSU$1RSP #1RSPResponse *+00100.00 Read Time Delay 1 RT1Response *1RT1+00100.00DC Read Time Delay 2 RT2 Page Page Short Prompt SP Error Messages Command 01WE Response *01WE27Address Error BAD ChecksumParity Error Command ErrorSyntax Error Value Error$1SUbyte 1byte 2byte 3byte Chapter Setup Information/SetUp CommandCommand Syntax Byte HEX Ascii Byte 1 Ascii Printable CharactersBaud Rate ParityCommand $1RS Response *31020102 Command $1WE Command $1RS Response *31070000Command $1WE Response Command $1SU31020000 Bit Command $1RR ResponseByte 2 Linefeed, Parity and Baud Rate BaudNormal addressing Chapter Delay Time Programming Delay Time Programming Page Command $1RT1 Response *+00100.00 Command $1T3+00050.00 Set T3 to 50 ms ResponseChapter Power Supply Symptom RS-485 Module is not responding to commands Chapter TroubleshootingSymptom RS-232 Module is not responding to commands Chapter Extended Addressing Command 01WE ResponseOpen/Close Channel Commands Typical system overview Command $1RD Response +00100.00 Typical $2RD +00123.45 Command 01OC ResponseCommand 01CC Response Command 02OC ResponseExtended Address Syntax Structured AddressingImplied CC Command OC and CC Command FormatsImplied OC Command Command ResponseExplicit Open and Close Channel Commands Command Response *01OC1D Single Command Module AddressCommand 01$1RD Response *+00100.00 Command 02OC Response 02OC1E ‘1E’ is the checksum Command 01CC Response 01CC11 ‘11’ is the checksumTransparent Mode Functions Chapter Transparent ModeA2400 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