Operating Manual IT251 Level converter, direction signal decoder and programmable impulse divider Features: Level conversion from TTL / RS 422 to HTL 10 ... 30 V and vice versa Programmable divider for error- free and position-true division of quadrature encoder Signals (A, B, 90°) Separate marker pulse divider with individual settings 300 kHz of maximum frequency Push-pull outputs for direct PLC interfacing 18 ...
Version: It25101e/ TJ/ Sep 03/5 It25102a/ hk/ Jan07 It2510_2b_oi/ ag/ Sep-15 Description: HTL input circuit resistors Brochure format, improved clarification of functions Design, Technical Specifications and Safety Instructions updated Legal notices: All contents included in this manual are protected by the terms of use and copyrights of motrona GmbH.
1. Safety Instructions and Responsibility 1.1. General Safety Instructions This operation manual is a significant component of the unit and includes important rules and hints about the installation, function and usage.
1.3. Installation The device is only allowed to be installed and operated within the permissible temperature range. Please ensure an adequate ventilation and avoid all direct contact between the device and hot or aggressive gases and liquids. Before installation or maintenance, the unit must be disconnected from all voltage-sources. Further it must be ensured that no danger can arise by touching the disconnected voltagesources.
2. Introduction IT 251 has been designed as a universal encoder interface for use with incremental encoder signals.
4. Connections and Terminal Assignments For frequency input, either the RS 422 inputs (D-SUB) or the 10 … 30 V HTL inputs can be used. The other inputs, which are not in use, must remain unconnected or must be disabled by corresponding DIL switch setting. The outputs provide impulse signals at TTL / RS422 level as well as at a 10 … 30 V HTL level, and either one or the other or both at a time can be used, whichever is applicable.
HTL input Low < 4.0 V High > 9.0 V 2.7 k Vref =5.5 V 6k B /A 1 A 2 6 /N 7 3 4 8 A /B 9 GND 9 5 /B GND It251_02c_oi_e.doc / Nov-15 +5.
5. Basic Switch Settings Upon commissioning, some basic settings must be done by switch DIL4. These settings select one of the possible standards for expressing the direction of rotation on inputs and outputs.
Configuration 8 7 6 DIL4 5 4 3 2 1 on on on off off on A 1** B A B A 3 B on on on off off on 2 Output direction standard 1 A B A B 2* Input direction standard 3* Connects the metallic housing of SUB-D-connector “RS422 Input” to terminal 12 Metallic housing of the SUB-D-connector “RS422 Input” is potential-free Connects the metallic housing of SUB-D-connector “RS422 Output” to terminal 12 Metallic housing of the SUB-D-connector “RS422 Output” is potential-free HTL Inputs disabled HTL In
this information, even when the phase is barely visible on an oscilloscope. For this kind of application, please set the A/B delay time by DIL switch 2, with consideration of your maximum output frequency. For division rates higher than 1:1, the phase displacement gets more and more close to a real 90º quadrature signal, independent of the input frequency. A/B time displacement when converting direction standard 2 or 3 to quadrature standard A/B Time Displacement DIL2 8 on on off off It251_02c_oi_e.
6. Setting of the Impulse Division Rate The incremental division rate for the A/B input pulses can be set by means of switch DIL1 and by positions 1 – 4 of switch DIL2. The marker pulse Z uses a separate divider and marker division is described later. The switch positions use a binary code like shown in the subsequent list. For technical reasons, a switch in ON position means logical “0” and a switch in OFF position means logical “1”.
7. Index Pulse Divider (Marker Pulse Z) 7.1. Unchanged index pulse (bypass) When you like to just bypass the index pulse from the input to the output (without any changes of frequency, position and pulse width), please use the following DIL switch settings: DIL3 8 7 6 5 4 3 2 1 on on on on on on on on DIL2 6 5 off off In this case you can ignore all further information given in this chapter. 7.2.
7.3. Setting of the division rate of the index divider These settings use the same rules and codes as shown with the main divider (see section 6) Index Divider [Z] DIL3 on = log.0, off = log.
DIL2 6 off 5 on Enlarged index pulse (one full encoder revolution) The pulse width of the enlarged output index pulse corresponds to the distance between two input index pulses (with index divider > 1 only).
8. Technical Specifications Power supply: Input voltage: Protection circuit: Ripple: Consumption: (unloaded encoder supply) Encoder supply: Incremental input: Connections: Output voltage: Output current: Connections: Signal levels: HTL internal resistance Channels: Frequency: Connections: Incremental output: Signal levels: Channels: Output current: Connections: Housing: Ambient temperature: Failure rate: Conformity & standards: It251_02c_oi_e.
9. Dimensions 79 mm (3.110’’) 40 mm (1.575’’) 91mm (3.583’’) 74 mm (2.193’’) Front view It251_02c_oi_e.
